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Guo H, Chen Y, Dong W, Lu S, Du Y, Duan L. Fecal Coprococcus, hidden behind abdominal symptoms in patients with small intestinal bacterial overgrowth. J Transl Med 2024; 22:496. [PMID: 38796441 PMCID: PMC11128122 DOI: 10.1186/s12967-024-05316-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Accepted: 05/20/2024] [Indexed: 05/28/2024] Open
Abstract
BACKGROUND Small intestinal bacterial overgrowth (SIBO) is the presence of an abnormally excessive amount of bacterial colonization in the small bowel. Hydrogen and methane breath test has been widely applied as a non-invasive method for SIBO. However, the positive breath test representative of bacterial overgrowth could also be detected in asymptomatic individuals. METHODS To explore the relationship between clinical symptoms and gut dysbiosis, and find potential fecal biomarkers for SIBO, we compared the microbial profiles between SIBO subjects with positive breath test but without abdominal symptoms (PBT) and healthy controls (HC) using 16S rRNA amplicon sequencing. RESULTS Fecal samples were collected from 63 SIBO who complained of diarrhea, distension, constipation, or abdominal pain, 36 PBT, and 55 HC. For alpha diversity, the Shannon index of community diversity on the genus level showed a tendency for a slight increase in SIBO, while the Shannon index on the predicted function was significantly decreased in SIBO. On the genus level, significantly decreased Bacteroides, increased Coprococcus_2, and unique Butyrivibrio were observed in SIBO. There was a significant positive correlation between saccharolytic Coprococcus_2 and the severity of abdominal symptoms. Differently, the unique Veillonella in the PBT group was related to amino acid fermentation. Interestingly, the co-occurrence network density of PBT was larger than SIBO, which indicates a complicated interaction of genera. Coprococcus_2 showed one of the largest betweenness centrality in both SIBO and PBT microbiota networks. Pathway analysis based on the Kyoto Encyclopedia of Genes and Genome (KEGG) database reflected that one carbon pool by folate and multiple amino acid metabolism were significantly down in SIBO. CONCLUSIONS This study provides valuable insights into the fecal microbiota composition and predicted metabolic functional changes in patients with SIBO. Butyrivibrio and Coprococcus_2, both renowned for their role in carbohydrate fermenters and gas production, contributed significantly to the symptoms of the patients. Coprococcus's abundance hints at its use as a SIBO marker. Asymptomatic PBT individuals show a different microbiome, rich in Veillonella. PBT's complex microbial interactions might stabilize the intestinal ecosystem, but further study is needed due to the core microbiota similarities with SIBO. Predicted folate and amino acid metabolism reductions in SIBO merit additional validation.
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Affiliation(s)
- Huaizhu Guo
- Department of Gastroenterology, Peking University Third Hospital, Beijing, China
| | - Yuzhu Chen
- Department of Gastroenterology, Peking University Third Hospital, Beijing, China
| | - Wenxin Dong
- Department of Pediatrics, Peking University Third Hospital, Beijing, China
| | - Siqi Lu
- Department of Gastroenterology, Peking University Third Hospital, Beijing, China
| | - Yanlin Du
- Department of Gastroenterology, Peking University Third Hospital, Beijing, China
| | - Liping Duan
- Department of Gastroenterology, Peking University Third Hospital, Beijing, China.
- International Institute of Population Health, Peking University Health Science Center, Beijing, China.
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2
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Lombardi M, Troisi J, Motta BM, Torre P, Masarone M, Persico M. Gut-Liver Axis Dysregulation in Portal Hypertension: Emerging Frontiers. Nutrients 2024; 16:1025. [PMID: 38613058 PMCID: PMC11013091 DOI: 10.3390/nu16071025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 03/27/2024] [Accepted: 03/30/2024] [Indexed: 04/14/2024] Open
Abstract
Portal hypertension (PH) is a complex clinical challenge with severe complications, including variceal bleeding, ascites, hepatic encephalopathy, and hepatorenal syndrome. The gut microbiota (GM) and its interconnectedness with human health have emerged as a captivating field of research. This review explores the intricate connections between the gut and the liver, aiming to elucidate how alterations in GM, intestinal barrier function, and gut-derived molecules impact the development and progression of PH. A systematic literature search, following PRISMA guidelines, identified 12 original articles that suggest a relationship between GM, the gut-liver axis, and PH. Mechanisms such as dysbiosis, bacterial translocation, altered microbial structure, and inflammation appear to orchestrate this relationship. One notable study highlights the pivotal role of the farnesoid X receptor axis in regulating the interplay between the gut and liver and proposes it as a promising therapeutic target. Fecal transplantation experiments further emphasize the pathogenic significance of the GM in modulating liver maladies, including PH. Recent advancements in metagenomics and metabolomics have expanded our understanding of the GM's role in human ailments. The review suggests that addressing the unmet need of identifying gut-liver axis-related metabolic and molecular pathways holds potential for elucidating pathogenesis and directing novel therapeutic interventions.
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Affiliation(s)
- Martina Lombardi
- Department of Chemistry and Biology “A. Zambelli”, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy;
- European Institute of Metabolomics (EIM) Foundation, Via G. Puccini, 3, 84081 Baronissi, SA, Italy
| | - Jacopo Troisi
- Department of Chemistry and Biology “A. Zambelli”, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy;
- European Institute of Metabolomics (EIM) Foundation, Via G. Puccini, 3, 84081 Baronissi, SA, Italy
- Department of Medicine, Surgery and Dentistry, “Scuola Medica Salernitana”, University of Salerno, 84081 Baronissi, SA, Italy; (B.M.M.); (P.T.); (M.M.)
| | - Benedetta Maria Motta
- Department of Medicine, Surgery and Dentistry, “Scuola Medica Salernitana”, University of Salerno, 84081 Baronissi, SA, Italy; (B.M.M.); (P.T.); (M.M.)
| | - Pietro Torre
- Department of Medicine, Surgery and Dentistry, “Scuola Medica Salernitana”, University of Salerno, 84081 Baronissi, SA, Italy; (B.M.M.); (P.T.); (M.M.)
| | - Mario Masarone
- Department of Medicine, Surgery and Dentistry, “Scuola Medica Salernitana”, University of Salerno, 84081 Baronissi, SA, Italy; (B.M.M.); (P.T.); (M.M.)
| | - Marcello Persico
- Department of Medicine, Surgery and Dentistry, “Scuola Medica Salernitana”, University of Salerno, 84081 Baronissi, SA, Italy; (B.M.M.); (P.T.); (M.M.)
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Höppner J, Krohn S, van den Munckhof EHA, Kallies R, Herber A, Zeller K, Tünnemann J, Matz-Soja M, Chatzinotas A, Böhm S, Hoffmeister A, Berg T, Engelmann C. Changes of the bacterial composition in duodenal fluid from patients with liver cirrhosis and molecular bacterascites. Sci Rep 2023; 13:23001. [PMID: 38155157 PMCID: PMC10754895 DOI: 10.1038/s41598-023-49505-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 12/08/2023] [Indexed: 12/30/2023] Open
Abstract
Small intestinal bacterial overgrowth and compositional changes of intestinal microbiota are pathomechanistic factors in liver cirrhosis leading to bacterial translocation and infectious complications. We analyzed the quantity and composition of duodenal bacterial DNA (bactDNA) in relation to bactDNA in blood and ascites of patients with liver cirrhosis. Duodenal fluid and corresponding blood and ascites samples from 103 patients with liver cirrhosis were collected. Non-liver disease patients (n = 22) served as controls. BactDNA was quantified by 16S-rRNA gene-based PCR. T-RFLP and 16S-rRNA amplicon sequencing were used to analyze bacterial composition. Duodenal bacterial diversity in cirrhosis was distinct to controls showing significantly higher abundances of Streptococcus, Enterococcus and Veillonella. Patients with bactDNA positive ascites revealed reduced spectrum of core microbiota with Streptococcus as key player of duodenal community and higher prevalence of Granulicatella proving presence of cirrhosis related intestinal dysbiosis. Regarding duodenal fluid bactDNA quantification, no significant differences were found between patients with cirrhosis and controls. Additionally, percentage of subjects with detectable bactDNA in blood did not differ between patients and controls. This study evaluated the diversity of bacterial DNA in different body specimens with potential implications on understanding how intestinal bacterial translocation may affect infectious complications in cirrhosis.
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Affiliation(s)
- Jim Höppner
- Division of Hepatology, Department of Medicine II, Leipzig University Medical Center, Leipzig, Germany
| | - Sandra Krohn
- Division of Hepatology, Department of Medicine II, Leipzig University Medical Center, Leipzig, Germany
| | | | - René Kallies
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Adam Herber
- Division of Hepatology, Department of Medicine II, Leipzig University Medical Center, Leipzig, Germany
| | - Katharina Zeller
- Endocrinology and Nephrology, University Hospital Leipzig, Leipzig, Germany
| | - Jan Tünnemann
- Division of Gastroenterology, Department of Medicine II, Leipzig University Medical Center, Leipzig, Germany
| | - Madlen Matz-Soja
- Division of Hepatology, Department of Medicine II, Leipzig University Medical Center, Leipzig, Germany
| | - Antonis Chatzinotas
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Stephan Böhm
- Max von Pettenkofer-Institute for Hygiene and Clinical Microbiology, Ludwig Maximilians-University, Munich, Germany
| | - Albrecht Hoffmeister
- Division of Gastroenterology, Department of Medicine II, Leipzig University Medical Center, Leipzig, Germany
| | - Thomas Berg
- Division of Hepatology, Department of Medicine II, Leipzig University Medical Center, Leipzig, Germany.
| | - Cornelius Engelmann
- Division of Hepatology, Department of Medicine II, Leipzig University Medical Center, Leipzig, Germany
- Institute for Liver and Digestive Health, Royal Free Campus, University College London, London, UK
- Department of Hepatology and Gastroenterology, Campus Virchow-Klinikum, Charité - Universitaetsmedizin Berlin, Berlin, Germany
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4
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Postma RJ, Broekhoven AG, Verspaget HW, de Boer H, Hankemeier T, Coenraad MJ, van Duinen V, van Zonneveld AJ. Novel Morphological Profiling Assay Connects ex Vivo Endothelial Cell Responses to Disease Severity in Liver Cirrhosis. GASTRO HEP ADVANCES 2023; 3:238-249. [PMID: 39129954 PMCID: PMC11307659 DOI: 10.1016/j.gastha.2023.10.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 10/16/2023] [Indexed: 08/13/2024]
Abstract
Background and Aims Endothelial cell (EC) dysfunction in response to circulating plasma factors is a known causal factor in many systemic diseases. However, no appropriate assay is available to investigate this causality ex vivo. In liver cirrhosis, systemic inflammation is identified as central mechanism in progression from compensated to decompensated cirrhosis (DC), but the role of ECs therein is unknown. We aimed to develop a novel ex vivo assay for assessing EC responses to patient-derived plasma (PDP) and assess the potential of this assay in a cohort of liver cirrhosis patients. Methods Image-based morphological profiling was utilized to assess the impact of PDP on cultured ECs. Endothelial cell (EC) monolayers were exposed to 25% stabilized PDP (20 compensated cirrhoses, 20 DCs, and 20 healthy controls (HCs). Single-cell morphological profiles were extracted by automated image-analysis following staining of multiple cellular components and high-content imaging. Patient profiles were created by dimension reduction and cell-to-patient data aggregation, followed by multivariate-analysis to stratify patients and identify discriminating features. Results Patient-derived plasma (PDP) exposure induced profound changes in EC morphology, displaying clear differences between controls and DC patients. Compensated cirrhosis patients showed overlap with healthy controls and DC patients. Supervised analysis showed Child-Pugh (CP) class could be predicted from EC morphology. Most importantly, CP-C patients displayed distinct EC phenotypes, in which mitochondrial changes were most discriminative. Conclusion Morphological profiling presents a viable tool to assess the endothelium ex vivo. We demonstrated that the EC phenotype corresponds with disease severity in liver cirrhosis. Moreover, our results suggest the presence of mitochondrial dysfunction in ECs of CP-C patient.
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Affiliation(s)
- Rudmer J. Postma
- Department of Internal Medicine (Nephrology) and the Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Annelotte G.C. Broekhoven
- Department of Gastroenterology and Hepatology, Leiden University Medical Center, Leiden, The Netherlands
| | - Hein W. Verspaget
- Department of Gastroenterology and Hepatology, Leiden University Medical Center, Leiden, The Netherlands
| | - Hetty de Boer
- Department of Internal Medicine (Nephrology) and the Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Thomas Hankemeier
- Department of Analytical BioSciences, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
| | - Minneke J. Coenraad
- Department of Gastroenterology and Hepatology, Leiden University Medical Center, Leiden, The Netherlands
| | - Vincent van Duinen
- Department of Internal Medicine (Nephrology) and the Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, The Netherlands
- MIMETAS B.V., Oegstgeest, The Netherlands
| | - Anton Jan van Zonneveld
- Department of Internal Medicine (Nephrology) and the Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, The Netherlands
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5
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Engelmann C, Zhang IW, Clària J. Mechanisms of immunity in acutely decompensated cirrhosis and acute-on-chronic liver failure. Liver Int 2023. [PMID: 37365995 DOI: 10.1111/liv.15644] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/26/2023] [Accepted: 05/31/2023] [Indexed: 06/28/2023]
Abstract
The identification of systemic inflammation (SI) as a central player in the orchestration of acute-on-chronic liver failure (ACLF) has opened new avenues for the understanding of the pathophysiological mechanisms underlying this disease condition. ACLF, which develops in patients with acute decompensation of cirrhosis, is characterized by single or multiple organ failure and high risk of short-term (28-day) mortality. Its poor outcome is closely associated with the severity of the systemic inflammatory response. In this review, we describe the key features of SI in patients with acutely decompensated cirrhosis and ACLF, including the presence of a high blood white cell count and increased levels of inflammatory mediators in systemic circulation. We also discuss the main triggers (i.e. pathogen- and damage-associated molecular patterns), the cell effectors (i.e. neutrophils, monocytes and lymphocytes), the humoral mediators (acute phase proteins, cytokines, chemokines, growth factors and bioactive lipid mediators) and the factors that influence the systemic inflammatory response that drive organ failure and mortality in ACLF. The role of immunological exhaustion and/or immunoparalysis in the context of exacerbated inflammatory responses that predispose ACLF patients to secondary infections and re-escalation of end-organ dysfunction and mortality are also reviewed. Finally, several new potential immunogenic therapeutic targets are debated.
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Affiliation(s)
- Cornelius Engelmann
- Medical Department, Division of Hepatology and Gastroenterology, Campus Virchow-Klinikum, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Berlin Institute of Health, Berlin, Germany
- Institute for Liver and Digestive Health, University College London, London, UK
| | - Ingrid W Zhang
- Medical Department, Division of Hepatology and Gastroenterology, Campus Virchow-Klinikum, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Berlin Institute of Health, Berlin, Germany
- European Foundation for the Study of Chronic Liver Failure (EF CLIF) and Grifols Chair, Barcelona, Spain
| | - Joan Clària
- European Foundation for the Study of Chronic Liver Failure (EF CLIF) and Grifols Chair, Barcelona, Spain
- Biochemistry and Molecular Genetics Service, Hospital Clínic-IDIBAPS CIBERehd, Barcelona, Spain
- Department of Biomedical Sciences, University of Barcelona, Barcelona, Spain
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6
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Zhu F, Zheng S, Zhao M, Shi F, Zheng L, Wang H. The regulatory role of bile acid microbiota in the progression of liver cirrhosis. Front Pharmacol 2023; 14:1214685. [PMID: 37416060 PMCID: PMC10320161 DOI: 10.3389/fphar.2023.1214685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 06/12/2023] [Indexed: 07/08/2023] Open
Abstract
Bile acids (BAs) are synthesized in liver tissue from cholesterol and are an important endocrine regulator and signaling molecule in the liver and intestine. It maintains BAs homeostasis, and the integrity of intestinal barrier function, and regulates enterohepatic circulation in vivo by modulating farnesoid X receptors (FXR) and membrane receptors. Cirrhosis and its associated complications can lead to changes in the composition of intestinal micro-ecosystem, resulting in dysbiosis of the intestinal microbiota. These changes may be related to the altered composition of BAs. The BAs transported to the intestinal cavity through the enterohepatic circulation are hydrolyzed and oxidized by intestinal microorganisms, resulting in changes in their physicochemical properties, which can also lead to dysbiosis of intestinal microbiota and overgrowth of pathogenic bacteria, induction of inflammation, and damage to the intestinal barrier, thus aggravating the progression of cirrhosis. In this paper, we review the discussion of BAs synthesis pathway and signal transduction, the bidirectional regulation of bile acids and intestinal microbiota, and further explore the role of reduced total bile acid concentration and dysregulated intestinal microbiota ratio in the development of cirrhosis, in order to provide a new theoretical basis for the clinical treatment of cirrhosis and its complications.
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Affiliation(s)
- Feng Zhu
- Heilongjiang University of Chinese Medicine, Harbin, China
| | - Shudan Zheng
- First Clinical School of Medicine, Heilongjiang University of Chinese Medicine, Harbin, China
| | - Mei Zhao
- First Clinical School of Medicine, Heilongjiang University of Chinese Medicine, Harbin, China
| | - Fan Shi
- First Clinical School of Medicine, Heilongjiang University of Chinese Medicine, Harbin, China
| | - Lihong Zheng
- Department of Gastroenterology, Fourth Affiliated Hospital, Heilongjiang University of Chinese Medicine, Harbin, China
| | - Haiqiang Wang
- Department of Gastroenterology, First Affiliated Hospital, Heilongjiang University of Chinese Medicine, Harbin, China
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7
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Di Vincenzo F, Nicoletti A, Negri M, Vitale F, Zileri Dal Verme L, Gasbarrini A, Ponziani FR, Cerrito L. Gut Microbiota and Antibiotic Treatments for the Main Non-Oncologic Hepato-Biliary-Pancreatic Disorders. Antibiotics (Basel) 2023; 12:1068. [PMID: 37370387 DOI: 10.3390/antibiotics12061068] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/10/2023] [Accepted: 06/15/2023] [Indexed: 06/29/2023] Open
Abstract
The gut microbiota is a pivotal actor in the maintenance of the balance in the complex interconnections of hepato-biliary-pancreatic system. It has both metabolic and immunologic functions, with an influence on the homeostasis of the whole organism and on the pathogenesis of a wide range of diseases, from non-neoplastic ones to tumorigenesis. The continuous bidirectional metabolic communication between gut and hepato-pancreatic district, through bile ducts and portal vein, leads to a continuous interaction with translocated bacteria and their products. Chronic liver disease and pancreatic disorders can lead to reduced intestinal motility, decreased bile acid synthesis and intestinal immune dysfunction, determining a compositional and functional imbalance in gut microbiota (dysbiosis), with potentially harmful consequences on the host's health. The modulation of the gut microbiota by antibiotics represents a pioneering challenge with striking future therapeutic opportunities, even in non-infectious diseases. In this setting, antibiotics are aimed at harmonizing gut microbial function and, sometimes, composition. A more targeted and specific approach should be the goal to pursue in the future, tailoring the treatment according to the type of microbiota modulation to be achieved and using combined strategies.
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Affiliation(s)
- Federica Di Vincenzo
- Internal Medicine and Gastroenterology, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, 00168 Rome, Italy
| | - Alberto Nicoletti
- Internal Medicine and Gastroenterology, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, 00168 Rome, Italy
| | - Marcantonio Negri
- Internal Medicine and Gastroenterology, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, 00168 Rome, Italy
| | - Federica Vitale
- Internal Medicine and Gastroenterology, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, 00168 Rome, Italy
| | - Lorenzo Zileri Dal Verme
- Internal Medicine and Gastroenterology, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, 00168 Rome, Italy
| | - Antonio Gasbarrini
- Internal Medicine and Gastroenterology, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, 00168 Rome, Italy
- Dipartimento Universitario di Medicina e Chirurgia Traslazionale, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Francesca Romana Ponziani
- Internal Medicine and Gastroenterology, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, 00168 Rome, Italy
- Dipartimento Universitario di Medicina e Chirurgia Traslazionale, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Lucia Cerrito
- Internal Medicine and Gastroenterology, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, 00168 Rome, Italy
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8
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Shah A, Ghoshal UC, Holtmann GJ. Unravelling the controversy with small intestinal bacterial overgrowth. Curr Opin Gastroenterol 2023; 39:211-218. [PMID: 37144539 DOI: 10.1097/mog.0000000000000928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
PURPOSE OF REVIEW The aim of this review is to summarize the current and emergent approaches to characterize the small intestinal microbiota and discuss the treatment options for management of small intestinal bacterial overgrowth (SIBO). RECENT FINDINGS This review captures the growing body of evidence for the role of SIBO, a type of small intestinal dysbiosis in the pathophysiology various gastrointestinal and extraintestinal disorders. We have highlighted the drawbacks of the available methods for characterizing the small intestinal microbiota and focus on the new culture-independent techniques to diagnose SIBO. Although recurrence is common, targeted modulation of the gut microbiome as a therapeutic option for management of SIBO is associated with improvement in symptoms and quality of life. SUMMARY As a first step to precisely characterize the potential link between SIBO and various disorders, we need to address the methodological limitations of the available traditional tests for diagnosing SIBO. There is an urgency to develop culture independent techniques that can be routinely used in clinical setting, that will enable characterization of the gastrointestinal microbiome and explore the response to antimicrobial therapy including the links between long-lasting symptom resolution and the microbiome.
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Affiliation(s)
- Ayesha Shah
- The University of Queensland, Faculty of Medicine and Faculty of Health and Behavioural Sciences
- Princess Alexandra Hospital, Department of Gastroenterology & Hepatology, Brisbane, QLD, Australia
| | - Uday C Ghoshal
- Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Gerald J Holtmann
- The University of Queensland, Faculty of Medicine and Faculty of Health and Behavioural Sciences
- Princess Alexandra Hospital, Department of Gastroenterology & Hepatology, Brisbane, QLD, Australia
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9
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Singh TP, Kadyan S, Devi H, Park G, Nagpal R. Gut microbiome as a therapeutic target for liver diseases. Life Sci 2023; 322:121685. [PMID: 37044173 DOI: 10.1016/j.lfs.2023.121685] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/27/2023] [Accepted: 04/05/2023] [Indexed: 04/14/2023]
Abstract
The prominent role of gut in regulating the physiology of different organs in a human body is increasingly acknowledged, to which the bidirectional communication between gut and liver is no exception. Liver health is modulated via different key components of gut-liver axis. The gut-derived products mainly generated from dietary components, microbial metabolites, toxins, or other antigens are sensed and transported to the liver through portal vein to which liver responds by secreting bile acids and antibodies. Therefore, maintaining a healthy gut microbiome can promote homeostasis of this gut-liver axis by regulating the intestinal barrier function and reducing the antigenic molecules. Conversely, liver secretions also regulate the gut microbiome composition. Disturbed homeostasis allows luminal antigens to reach liver leading to impaired liver functioning and instigating liver disorders. The perturbations in gut microbiome, permeability, and bile acid pool have been associated with several liver disorders, although precise mechanisms remain largely unresolved. Herein, we discuss functional fingerprints of a healthy gut-liver axis while contemplating mechanistic understanding of pathophysiology of liver diseases and plausible role of gut dysbiosis in different diseased states of liver. Further, novel therapeutic approaches to prevent the severity of liver disorders are discussed in this review.
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Affiliation(s)
- Tejinder Pal Singh
- Department of Dairy Microbiology, College of Dairy Science and Technology, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, Haryana 125004, India
| | - Saurabh Kadyan
- Department of Nutrition and Integrative Physiology, College of Health and Human Sciences, Florida State University, Tallahassee, FL 32306, USA
| | - Harisha Devi
- Department of Dairy Microbiology, College of Dairy Science and Technology, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, Haryana 125004, India
| | - Gwoncheol Park
- Department of Nutrition and Integrative Physiology, College of Health and Human Sciences, Florida State University, Tallahassee, FL 32306, USA
| | - Ravinder Nagpal
- Department of Nutrition and Integrative Physiology, College of Health and Human Sciences, Florida State University, Tallahassee, FL 32306, USA.
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10
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Tansel A, Levinthal DJ. Understanding Our Tests: Hydrogen-Methane Breath Testing to Diagnose Small Intestinal Bacterial Overgrowth. Clin Transl Gastroenterol 2023; 14:e00567. [PMID: 36744854 PMCID: PMC10132719 DOI: 10.14309/ctg.0000000000000567] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 01/26/2023] [Indexed: 02/07/2023] Open
Abstract
There is increasing appreciation that small intestinal bacterial overgrowth (SIBO) drives many common gastrointestinal symptoms, including diarrhea, bloating, and abdominal pain. Breath testing via measurement of exhaled hydrogen and methane gases following ingestion of a readily metabolized carbohydrate has become an important noninvasive testing paradigm to help diagnose SIBO. However, because of a number of physiological and technical considerations, how and when to use breath testing in the diagnosis of SIBO remains a nuanced clinical decision. This narrative review provides a comprehensive overview of breath testing paradigms including the indications for testing, how to administer the test, and how patient factors influence breath testing results. We also explore the performance characteristics of breath testing (sensitivity, specificity, positive and negative predictive values, likelihood ratios, and diagnostic odds ratio). Additionally, we describe complementary and alternative tests for diagnosing SIBO. We discuss applications of breath testing for research. Current estimates of SIBO prevalence among commonly encountered high-risk populations are reviewed to provide pretest probability estimates under a variety of clinical situations. Finally, we discuss how to integrate breath test performance characteristics into clinical care decisions using clinical predictors and the Fagan nomogram.
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Affiliation(s)
- Aylin Tansel
- Department of Medicine, Division of Gastroenterology, Hepatology, and Nutrition, University of Pittsburgh Medical Center, Pittsburgh, USA
| | - David J. Levinthal
- Department of Medicine, Division of Gastroenterology, Hepatology, and Nutrition, University of Pittsburgh Medical Center, Pittsburgh, USA
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11
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Chen C, Wang Z, Ding Y, Qin Y. Tumor microenvironment-mediated immune evasion in hepatocellular carcinoma. Front Immunol 2023; 14:1133308. [PMID: 36845131 PMCID: PMC9950271 DOI: 10.3389/fimmu.2023.1133308] [Citation(s) in RCA: 42] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 02/02/2023] [Indexed: 02/12/2023] Open
Abstract
Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and is the third leading cause of tumor-related mortality worldwide. In recent years, the emergency of immune checkpoint inhibitor (ICI) has revolutionized the management of HCC. Especially, the combination of atezolizumab (anti-PD1) and bevacizumab (anti-VEGF) has been approved by the FDA as the first-line treatment for advanced HCC. Despite great breakthrough in systemic therapy, HCC continues to portend a poor prognosis owing to drug resistance and frequent recurrence. The tumor microenvironment (TME) of HCC is a complex and structured mixture characterized by abnormal angiogenesis, chronic inflammation, and dysregulated extracellular matrix (ECM) remodeling, collectively contributing to the immunosuppressive milieu that in turn prompts HCC proliferation, invasion, and metastasis. The tumor microenvironment coexists and interacts with various immune cells to maintain the development of HCC. It is widely accepted that a dysfunctional tumor-immune ecosystem can lead to the failure of immune surveillance. The immunosuppressive TME is an external cause for immune evasion in HCC consisting of 1) immunosuppressive cells; 2) co-inhibitory signals; 3) soluble cytokines and signaling cascades; 4) metabolically hostile tumor microenvironment; 5) the gut microbiota that affects the immune microenvironment. Importantly, the effectiveness of immunotherapy largely depends on the tumor immune microenvironment (TIME). Also, the gut microbiota and metabolism profoundly affect the immune microenvironment. Understanding how TME affects HCC development and progression will contribute to better preventing HCC-specific immune evasion and overcoming resistance to already developed therapies. In this review, we mainly introduce immune evasion of HCC underlying the role of immune microenvironment, describe the dynamic interaction of immune microenvironment with dysfunctional metabolism and the gut microbiome, and propose therapeutic strategies to manipulate the TME in favor of more effective immunotherapy.
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Affiliation(s)
| | | | | | - Yanru Qin
- Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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12
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Zhang J, Zao X, Zhang J, Guo Z, Jin Q, Chen G, Gan D, Du H, Ye Y. Is it possible to intervene early cirrhosis by targeting toll-like receptors to rebalance the intestinal microbiome? Int Immunopharmacol 2023; 115:109627. [PMID: 36577151 DOI: 10.1016/j.intimp.2022.109627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/13/2022] [Accepted: 12/19/2022] [Indexed: 12/27/2022]
Abstract
Cirrhosis is a progressive chronic liver disease caused by one or more causes and characterized by diffuse fibrosis, pseudolobules, and regenerated nodules. Once progression to hepatic decompensation, the function of the liver and other organs is impaired and almost impossible to reverse and recover, which often results in hospitalization, impaired quality of life, and high mortality. However, in the early stage of cirrhosis, there seems to be a possibility of cirrhosis reversal. The development of cirrhosis is related to the intestinal microbiota and activation of toll-like receptors (TLRs) pathways, which could regulate cell proliferation, apoptosis, expression of the hepatomitogen epiregulin, and liver inflammation. Targeting regulation of intestinal microbiota and TLRs pathways could affect the occurrence and development of cirrhosis and its complications. In this paper, we first reviewed the dynamic change of intestinal microbiota and TLRs during cirrhosis progression. And further discussed the interaction between them and potential therapeutic targets to reverse early staged cirrhosis.
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Affiliation(s)
- Jiaxin Zhang
- Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China; Institute of Liver Diseases, Beijing University of Chinese Medicine, Beijing, China
| | - Xiaobin Zao
- Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China; Institute of Liver Diseases, Beijing University of Chinese Medicine, Beijing, China
| | - Jiaying Zhang
- School of Mechanical Engineering and Automation, Beihang University, Beijing, China
| | - Ziwei Guo
- Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China
| | - Qian Jin
- Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China
| | - Guang Chen
- Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China; Institute of Liver Diseases, Beijing University of Chinese Medicine, Beijing, China
| | - Da'nan Gan
- Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China; Institute of Liver Diseases, Beijing University of Chinese Medicine, Beijing, China
| | - Hongbo Du
- Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China; Institute of Liver Diseases, Beijing University of Chinese Medicine, Beijing, China
| | - Yong'an Ye
- Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China; Institute of Liver Diseases, Beijing University of Chinese Medicine, Beijing, China.
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Impact of Small Intestinal Bacterial Overgrowth in Patients with Inflammatory Bowel Disease and Other Gastrointestinal Disorders-A Retrospective Analysis in a Tertiary Single Center and Review of the Literature. J Clin Med 2023; 12:jcm12030935. [PMID: 36769583 PMCID: PMC9917804 DOI: 10.3390/jcm12030935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/20/2023] [Accepted: 01/22/2023] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Small intestinal bacterial overgrowth (SIBO) is often found in patients with gut dysbiosis such as irritable bowel syndrome. Recently, the association of SIBO and inflammatory bowel disease (IBD) has been described in some cases. While clinical symptoms might be similar in IBD and SIBO, treatment is quite different for both diseases. Therefore, the differentiation between SIBO or a flare in IBD patients is key to optimizing treatment for these patients. METHODS We retrospectively investigated our patients with IBD receiving a glucose breath test for SIBO and correlated the results with the clinical symptoms (clinical remission or active disease). RESULTS 128 patients with the diagnosis "colitis" were analyzed in our cohort. Fifty-three (41.4%) patients had Crohn's disease and 22 (17.2%) patients were suffering from ulcerative colitis. Seventy-four (57.8%) were female and 54 (42.2%) were male patients. A total of 18 (14.1%) patients had a positive testing for SIBO. Eleven (61.1%) cases were associated with CD patients and two (11.1%) with UC. IBD patients in clinical remission had a positive SIBO in six (19.4%) cases, while IBD patients with active disease were positive in nine (15.3%) cases. The proportion of positive SIBO in active IBD patients was higher; however, it did not reach significance. Older age was a risk factor for SIBO in patients with CD (p < 0.003). CONCLUSIONS In our study, we could show that an increased amount of SIBO was found in IBD patients and was especially more frequent in patients with CD than in those with UC. In UC patients, SIBO rates were not different to patients with other gastrointestinal diseases investigated (e.g., infectious colitis, collagenous colitis, or irritable bowel syndrome). In active IBD, positive SIBO was detected more often numerically compared to quiescent disease; however, due to the low number of patients included, it was not significant. However, older age was a significant risk factor for SIBO in patients with CD. SIBO is of clinical relevance in the vulnerable patient cohort with IBD, and its real prevalence and impact needs to be investigated in further and larger clinical trials.
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Luo M, Xin RJ, Hu FR, Yao L, Hu SJ, Bai FH. Role of gut microbiota in the pathogenesis and therapeutics of minimal hepatic encephalopathy via the gut-liver-brain axis. World J Gastroenterol 2023; 29:144-156. [PMID: 36683714 PMCID: PMC9850958 DOI: 10.3748/wjg.v29.i1.144] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 11/23/2022] [Accepted: 12/14/2022] [Indexed: 01/04/2023] Open
Abstract
Minimal hepatic encephalopathy (MHE) is a frequent neurological and psychiatric complication of liver cirrhosis. The precise pathogenesis of MHE is complicated and has yet to be fully elucidated. Studies in cirrhotic patients and experimental animals with MHE have indicated that gut microbiota dysbiosis induces systemic inflammation, hyperammonemia, and endotoxemia, subsequently leading to neuroinflammation in the brain via the gut-liver-brain axis. Related mechanisms initiated by gut microbiota dysbiosis have significant roles in MHE pathogenesis. The currently available therapeutic strategies for MHE in clinical practice, including lactulose, rifaximin, probiotics, synbiotics, and fecal microbiota transplantation, exert their effects mainly by modulating gut microbiota dysbiosis. Microbiome therapies for MHE have shown promised efficacy and safety; however, several controversies and challenges regarding their clinical use deserve to be intensively discussed. We have summarized the latest research findings concerning the roles of gut microbiota dysbiosis in the pathogenesis of MHE via the gut-liver-brain axis as well as the potential mechanisms by which microbiome therapies regulate gut microbiota dysbiosis in MHE patients.
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Affiliation(s)
- Ming Luo
- Department of Gastroenterology, People’s Hospital of Ningxia Hui Autonomous Region, Yinchuan 750021, Ningxia Hui Autonomous Region, China
| | - Rui-Juan Xin
- Department of Gastroenterology, People’s Hospital of Ningxia Hui Autonomous Region, Yinchuan 750021, Ningxia Hui Autonomous Region, China
| | - Fang-Rui Hu
- Department of Gastroenterology, People’s Hospital of Ningxia Hui Autonomous Region, Yinchuan 750021, Ningxia Hui Autonomous Region, China
| | - Li Yao
- Department of Gastroenterology, People’s Hospital of Ningxia Hui Autonomous Region, Yinchuan 750021, Ningxia Hui Autonomous Region, China
| | - Sheng-Juan Hu
- Department of Gastroenterology, People’s Hospital of Ningxia Hui Autonomous Region, Yinchuan 750021, Ningxia Hui Autonomous Region, China
| | - Fei-Hu Bai
- Department of Gastroenterology, People’s Hospital of Ningxia Hui Autonomous Region, Yinchuan 750021, Ningxia Hui Autonomous Region, China
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15
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Gudan A, Jamioł-Milc D, Hawryłkowicz V, Skonieczna-Żydecka K, Stachowska E. The Prevalence of Small Intestinal Bacterial Overgrowth in Patients with Non-Alcoholic Liver Diseases: NAFLD, NASH, Fibrosis, Cirrhosis-A Systematic Review, Meta-Analysis and Meta-Regression. Nutrients 2022; 14:nu14245261. [PMID: 36558421 PMCID: PMC9783356 DOI: 10.3390/nu14245261] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/27/2022] [Accepted: 11/30/2022] [Indexed: 12/14/2022] Open
Abstract
Bacterial overgrowth in the small intestine (SIBO) is a pathological growth of the intestinal microbiota in the small intestine that causes clinical symptoms and can lead to digestive and absorption disorders. There is increasing evidence that people with NAFLD have a distinct gut microflora profile as well metabolome changes compared to people without NAFLD. Thorough analysis of observational and RCT studies in the current databases (EMBASE, Web of Science, PubMed, Cinahl, Clinical Trials) was conducted from 3 November 2021 to 21 June 2022. The following inclusion criteria were applied: confirmed NAFLD, NASH, LIVER FIBROSIS, CIRRHOSIS due to steatosis; diagnostic methods of liver diseases—biopsy, elastography, transabdominal ultrasound; nonalcoholic fatty liver disease activity score; confirmed SIBO; diagnostic methods of SIBO−breath tests (hydrogen test; methane test and mix test; duodenal and jejunal aspiration before any type of intervention; adults above 18yo; number of participants ≥20; full articles. We excluded review articles, populations with HBV/HCV infection and alcohol etiology and interventions that may affect NAFLD or SIBO treatment. The quality of each study methodology was classified by means of the Cochrane Collaboration’s tool (RCT) and Newcastle—Ottawa Quality Assessment Scale adapted for cross-sectional, cohort and case-control studies. The random effects meta-analysis of outcomes for which ≥2 studies contributed data was conducted. The I2 index to measure heterogeneity and the χ2 test of homogeneity (statistically significant heterogeneity p < 0.05) were applied. For categorical outcome, the pooled event rate (effect size) was calculated. This systematic review was reported according to PRISMA reporting guidelines. We initially identified 6643 studies, from which 18 studies were included in final meta-analysis. The total number of patients was 1263. Accepted SIBO diagnostic methods were both available breath tests (n-total = 15) and aspirate culture (n-total = 3). We found that among patients with non-alcoholic liver diseases, the random overall event rate of SIBO was 0.350 (95% CI, 0.244−0.472), p = 0.017. The subgroup analysis regarding a type of diagnosis revealed that the lowest ER was among patients who developed simultaneously NAFLD, NASH and fibrosis: 0.197 (95% CI, 0.054−0.510) as compared to other annotated subgroups. The highest prevalence of SIBO was observed in the NASH subgroup: 0.411 (95% CI, 0.219−0.634). There were no statistically significant differences in the prevalence of SIBO in different subgroups (p = 0.854). Statistically significant heterogeneity between studies was estimated (I2 = 86.17%, p = 0.00). Egger’s test did not indicate a publication bias (df = 16, p = 0.885). A meta-regression using a random-effects model revealed that higher percentage of males in the population with liver diseases is a predisposing factor toward SIBO (Q = 4.11, df = 1, p = 0.0426 with coefficient = 0.0195, SE = 0.0096, Z = 2.03). We showed that the prevalence of SIBO in patients with chronic non-alcoholic liver diseases can be as high as 35%, and it increases with the percentage of men in the population. The prevalence of SIBO does not differ significantly depending on the type of chronic liver disease. Despite the high heterogeneity and moderate and low quality of included studies, our meta-analysis suggests the existence of a problem of SIBO in the population of patients with non-alcoholic liver diseases, and the presence of SIBO, in turn, determines the therapeutic treatment of such type of patients, which indicates the need for further research in this area. The study protocol was registered with the international Prospective Register of Systematic Reviews (PROSPERO ID: CRD42022341473).
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Affiliation(s)
- Anna Gudan
- Department of Human Nutrition and Metabolomics, Pomeranian Medical University in Szczecin, ul. Władysława Broniewskiego 24, 71-460 Szczecin, Poland
| | - Dominika Jamioł-Milc
- Department of Human Nutrition and Metabolomics, Pomeranian Medical University in Szczecin, ul. Władysława Broniewskiego 24, 71-460 Szczecin, Poland
- Correspondence: (D.J.-M.); (K.S.-Ż.); Tel.: +48-91-441-48-06 (D.J.-M. & K.S.-Ż.); Fax: +48-91-441-48-07 (D.J.-M. & K.S.-Ż.)
| | - Victoria Hawryłkowicz
- Department of Human Nutrition and Metabolomics, Pomeranian Medical University in Szczecin, ul. Władysława Broniewskiego 24, 71-460 Szczecin, Poland
| | - Karolina Skonieczna-Żydecka
- Department of Biochemical Sciences, Pomeranian Medical University in Szczecin, ul. Władysława Broniewskiego 24, 71-460 Szczecin, Poland
- Correspondence: (D.J.-M.); (K.S.-Ż.); Tel.: +48-91-441-48-06 (D.J.-M. & K.S.-Ż.); Fax: +48-91-441-48-07 (D.J.-M. & K.S.-Ż.)
| | - Ewa Stachowska
- Department of Human Nutrition and Metabolomics, Pomeranian Medical University in Szczecin, ul. Władysława Broniewskiego 24, 71-460 Szczecin, Poland
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Chang C, Yuan X, Zhang X, Chen X, Li K. Gastrointestinal Microbiome and Multiple Health Outcomes: Umbrella Review. Nutrients 2022; 14:3726. [PMID: 36145102 PMCID: PMC9505003 DOI: 10.3390/nu14183726] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 08/29/2022] [Accepted: 09/08/2022] [Indexed: 11/22/2022] Open
Abstract
In recent years, there has been growing concern about the impact of the gastrointestinal microbiome on human health outcomes. To clarify the evidence for a link between the gastrointestinal microbiome and a variety of health outcomes in humans, we conducted an all-encompassing review of meta-analyses and systematic reviews that included 195 meta-analyses containing 950 unique health outcomes. The gastrointestinal microbiome is related to mortality, gastrointestinal disease, immune and metabolic outcomes, neurological and psychiatric outcomes, maternal and infant outcomes, and other outcomes. Existing interventions for intestinal microbiota (such as probiotics, fecal microbiota transplant, etc.) are generally safe and beneficial to a variety of human health outcomes, but the quality of evidence is not high, and more detailed and well-designed randomized controlled trials are necessary.
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Affiliation(s)
- Chengting Chang
- West China School of Nursing, Sichuan University/West China Hospital, Sichuan University, 37 Guo Xue Rd., Chengdu 610041, China
| | - Xingzhu Yuan
- West China School of Nursing, Sichuan University/West China Hospital, Sichuan University, 37 Guo Xue Rd., Chengdu 610041, China
| | - Xingxia Zhang
- Department of Organization, West China Hospital, Sichuan University, 37 Guo Xue Rd., Chengdu 610041, China
| | - Xinrong Chen
- West China School of Nursing, Sichuan University/West China Hospital, Sichuan University, 37 Guo Xue Rd., Chengdu 610041, China
| | - Ka Li
- West China School of Nursing, Sichuan University/West China Hospital, Sichuan University, 37 Guo Xue Rd., Chengdu 610041, China
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17
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Guan H, Zhang X, Kuang M, Yu J. The gut-liver axis in immune remodeling of hepatic cirrhosis. Front Immunol 2022; 13:946628. [PMID: 37408838 PMCID: PMC10319400 DOI: 10.3389/fimmu.2022.946628] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 07/11/2022] [Indexed: 07/07/2023] Open
Abstract
In healthy settings, the gut-liver axis allows host-microbiota communications and mediates immune homeostasis through bidirectional regulation. Meanwhile, in diseases, gut dysbiosis, combined with an impaired intestinal barrier, introduces pathogens and their toxic metabolites into the system, causing massive immune alternations in the liver and other extrahepatic organs. Accumulating evidence suggests that these immune changes are associated with the progression of many liver diseases, especially hepatic cirrhosis. Pathogen-associated molecular patterns that originated from gut microbes directly stimulate hepatocytes and liver immune cells through different pattern recognition receptors, a process further facilitated by damage-associated molecular patterns released from injured hepatocytes. Hepatic stellate cells, along with other immune cells, contribute to this proinflammatory and profibrogenic transformation. Moreover, cirrhosis-associated immune dysfunction, an imbalanced immune status characterized by systemic inflammation and immune deficiency, is linked to gut dysbiosis. Though the systemic inflammation hypothesis starts to link gut dysbiosis to decompensated cirrhosis from a clinical perspective, a clearer demonstration is still needed for the role of the gut-liver-immune axis in cirrhosis progression. This review discusses the different immune states of the gut-liver axis in both healthy and cirrhotic settings and, more importantly, summarizes the current evidence about how microbiota-derived immune remodeling contributes to the progression of hepatic cirrhosis via the gut-liver axis.
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Affiliation(s)
- Huayu Guan
- Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China
- Department of Liver Surgery, Center of Hepato-Pancreato-Biliary Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xiang Zhang
- Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Ming Kuang
- Department of Liver Surgery, Center of Hepato-Pancreato-Biliary Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jun Yu
- Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China
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18
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Evidence-Based and Emerging Diet Recommendations for Small Bowel Disorders. Am J Gastroenterol 2022; 117:958-964. [PMID: 35404303 PMCID: PMC9169759 DOI: 10.14309/ajg.0000000000001764] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 04/01/2022] [Indexed: 02/06/2023]
Abstract
Diet plays a key role in the manifestation and severity of gastrointestinal symptoms, with increasing research interest on the role of diet in small bowel disorders. There are predominantly 3 small bowel conditions that have potential dietary interventions. Self-reported nonceliac gluten/wheat sensitivity is prevalent. Although gluten is believed to be a potential trigger for symptoms, other components of wheat may also be triggers, including fructans, alpha-amylase trypsin inhibitors, and wheat germ agglutinins. The diagnosis can be challenging, given the lack of validated biomarkers. A gluten-free diet that excludes the abovementioned triggers is the cornerstone of treatment; however, unlike celiac disease, there is uncertainty about the level of adherence or whether the gluten-free diet is a lifelong intervention. Several primary gastrointestinal disorders are associated with an increase in inflammatory cells including eosinophils. Diet seems to be an important driver of disease pathogenesis in eosinophilic gastroenteritis, with elimination and elemental diets showing promise in management, with further robust trials required. Small intestinal bacterial overgrowth is an example of microbial dysbiosis, with renewed interest in diet being postulated to cause an adaptive change of the microbes colonizing the small intestine. However, the diagnosis of small intestinal bacterial overgrowth is limited by a lack of sensitive and specific tests, with significant knowledge gaps in relation to therapeutic measures to manage and cure small intestinal bacterial overgrowth. Currently, antimicrobials are the established management option. There have been significant clinical advances in dietary interventions related to the small bowel, but this area is currently a novel and advancing field for both patients and clinicians.
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Concomitant Irritable Bowel Syndrome Does Not Influence the Response to Antimicrobial Therapy in Patients with Functional Dyspepsia. Dig Dis Sci 2022; 67:2299-2309. [PMID: 34392491 DOI: 10.1007/s10620-021-07149-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 05/03/2021] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIMS Antimicrobial therapy improves symptoms in patients with irritable bowel syndrome (IBS), but the efficacy in functional dyspepsia (FD) is largely unknown. While FD and IBS frequently overlap, it is unknown if concomitant IBS in FD alters the response to antimicrobial therapy in FD. Thus, we aimed to assess and compare the effect of antimicrobial therapy on visceral sensory function and symptom improvement in FD patients with and without IBS. METHODS Adult patients with FD with or without IBS received rifaximin 550 mg BD for 10 days, followed by a 6-week follow-up period. The total gastrointestinal symptom score as measured by the SAGIS (Structured Assessment of Gastrointestinal Symptoms) questionnaire and subscores (dyspepsia, diarrhea, and constipation), symptom response to a standardized nutrient challenge and normalization of the glucose breath tests were measured. RESULTS Twenty-one consecutive adult patients with FD and 14/21 with concomitant IBS were recruited. Treatment with rifaximin resulted in a significant (p = 0.017) improvement in the total SAGIS score from 34.7 (± 15.4) at baseline to 26.0 (± 16.8) at 2 weeks and 25.6 (± 17.8) at 6 weeks post-treatment. Similarly, compared to baseline there was a statistically significant improvement in SAGIS subscores for dyspepsia and diarrhea (all p < 0.05) and effects persisted for 6 weeks post-treatment. Similarly, the symptom score (and subscores) following a standardized nutrient challenge improved significantly (p < 0.001) 2 weeks post-treatment. The presence of concomitant IBS did not significantly influence the improvement of symptoms after antibiotic therapy (all p > 0.5). CONCLUSIONS In FD patients, the response to antimicrobial therapy with rifaximin is not influenced by concomitant IBS symptoms.
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Dicheva DT, Andreev DN. Pathogenetic and clinical significance of the gut-liver microbiota axis. MEDITSINSKIY SOVET = MEDICAL COUNCIL 2022:69-75. [DOI: 10.21518/2079-701x-2022-16-7-69-75] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/28/2024]
Abstract
Today, nonalcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) account for more than 50% of chronic liver diseases and cirrhosis in developed countries. The clinical significance of these pathologies lies in the formation of liver fibrosis and, therefore, in the increased risk of liver cirrhosis and hepatocellular carcinoma, which are life-threatening conditions. NAFLD is based on obesity and insulin resistance, whereas alcohol consumption is central to the etiopathogenesis of ALD. Recently, the role of the gut-liver microbiota axis in the genesis of NAFLD and ALD has also received increasing attention. Changes in qualitative and quantitative composition of intestinal microbiota and alterations of barrier function of intestinal mucosa can lead to entry of intraluminal antigens through portal vein system into the liver, inducing damage to hepatocytes and activation of proinflammatory processes. It is shown that in patients with CLD (NAFLD and ALD) there is an increase in the permeability of the intestinal mucosa and dysbiotic changes of the intestinal microbiome. The role of the gut-liver microbiota axis is well described in the genesis of NAFLD and ALD. Chronic alcohol consumption leads to increased colonies of Gram-negative bacteria in the intestinal mucosa and, therefore, to the accumulation of endotoxins (lipopolysaccharide components of bacterial cell membranes). Acetaldehyde produced by ADH of the intestinal epithelium stimulates tyrosine phosphorylation of tight cell contacts, increasing intestinal mucosal permeability, which leads to translocation of endotoxins into the portal bloodstream. Obesity is a major risk factor for NAFLD, which is also associated with dysbiotic changes in the intestinal microbiome. Obese individuals have increased Firmicutes, decreased Bacteroidetes, mediated reduction of short-chain fatty acid synthesis and increased intestinal wall permeability due to disruption of intercellular dense contacts, which leads to increased translocation of bacteria and endotoxins into the systemic bloodstream.
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Affiliation(s)
- D. T. Dicheva
- Yevdokimov Moscow State University of Medicine and Dentistry
| | - D. N. Andreev
- Yevdokimov Moscow State University of Medicine and Dentistry
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Scarpellini E, Abenavoli L, Cassano V, Rinninella E, Sorge M, Capretti F, Rasetti C, Svegliati Baroni G, Luzza F, Santori P, Sciacqua A. The Apparent Asymmetrical Relationship Between Small Bowel Bacterial Overgrowth, Endotoxemia, and Liver Steatosis and Fibrosis in Cirrhotic and Non-Cirrhotic Patients: A Single-Center Pilot Study. Front Med (Lausanne) 2022; 9:872428. [PMID: 35559337 PMCID: PMC9090439 DOI: 10.3389/fmed.2022.872428] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 03/18/2022] [Indexed: 11/18/2022] Open
Abstract
Introduction Gut microbiota are a complex ecosystem harboring our intestine. They maintain human body equilibrium, while their derangement, namely, “dysbiosis“, has been associated with several gastrointestinal diseases, such as liver steatosis (NAFLD) and liver cirrhosis. Small intestinal bacterial overgrowth (SIBO) is an example of dysbiosis of the upper gastrointestinal (GI) tract. Aim The aim of this study is to evaluate the relationship between SIBO and levels of endotoxemia and grade of liver steatosis (LS) and liver fibrosis (LF) in hepatologic patients. Materials and Methods Consecutive outpatients referred to our hepatology clinic were tested for SIBO by the lactulose breath test (LBT) and peripheral blood levels of endotoxemia; LS grading and LF were assessed by abdominal ultrasound and transient elastography, respectively. Results Fifty-two consecutive patients (17 with alcohol abuse (4.5 ± 0.8 alcohol units per day), 4 with HCV and 2 with HBV infection, 24 of metabolic origin, 2 of autoimmune origin, and 3 with cholangiopathies; mean age 54.7 ± 8.3 years, 31 F, BMI 24.1 ± 1.1 Kg/m2) and 14 healthy volunteers (HV) (mean age 50.1 ± 4.3 years, 9 F, BMI 23.3 ± 1.1 Kg/m2) were enrolled. SIBO prevalence was significantly higher in cirrhotic (LC) vs. non-cirrhotic (LNC) patients and vs. HV (all, p < 0.05), with a significant positive trend according to Child-Pugh status (all, p < 0.05). SIBO prevalence was not correlated with LS stages (all, p = NS). Consensually, endotoxin levels were significantly higher in LC vs. LNC and vs. HV (all, p < 0.05) and significantly correlated with LF in patients with LC, according to Child-Pugh status (all, p < 0.05). Conclusion This study shows that SIBO prevalence and relative endotoxin blood levels seem to be significantly associated with the grade of LF vs. LS in LC. SIBO is also present under pre-cirrhotic conditions, but its prevalence seems to correlate with liver disease irreversible derangement.
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Affiliation(s)
- E. Scarpellini
- Hepatology and Internal Medicine Unit, “Madonna del Soccorso” General Hospital, San Benedetto del Tronto, Italy
- T.A.R.G.I.D., Gasthuisberg University Hospital, KULeuven, Lueven, Belgium
- *Correspondence: E. Scarpellini
| | - L. Abenavoli
- Department of Health Sciences, University “Magna Græcia”, Catanzaro, Italy
| | - V. Cassano
- Department of Medical and Surgical Sciences, University “Magna Græcia”, Catanzaro, Italy
| | - E. Rinninella
- Clinical Nutrition Unit, Department of Medical and Surgical Sciences, Fondazione Policlinico A. Gemelli IRCCS, Rome, Italy
- Department of Translational Medicine and Surgery, Università Cattolica del Sacro Cuore, Rome, Italy
| | - M. Sorge
- Gastroenterology and Endoscopy Unit “Madonna del Soccorso” General Hospital, San Benedetto del Tronto, Italy
| | - F. Capretti
- Gastroenterology and Endoscopy Unit “Madonna del Soccorso” General Hospital, San Benedetto del Tronto, Italy
| | - C. Rasetti
- Hepatology and Internal Medicine Unit, “Madonna del Soccorso” General Hospital, San Benedetto del Tronto, Italy
| | - G. Svegliati Baroni
- Gastroenterology Clinic, “Riuniti University Hospital”, Polytechnics University of Marche, Ancona, Italy
| | - F. Luzza
- Department of Health Sciences, University “Magna Græcia”, Catanzaro, Italy
| | - P. Santori
- Hepatology and Internal Medicine Unit, “Madonna del Soccorso” General Hospital, San Benedetto del Tronto, Italy
| | - A. Sciacqua
- Department of Medical and Surgical Sciences, University “Magna Græcia”, Catanzaro, Italy
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22
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Silveira MAD, Bilodeau S, Greten TF, Wang XW, Trinchieri G. The gut-liver axis: host microbiota interactions shape hepatocarcinogenesis. Trends Cancer 2022; 8:583-597. [PMID: 35331674 DOI: 10.1016/j.trecan.2022.02.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 02/18/2022] [Accepted: 02/24/2022] [Indexed: 12/21/2022]
Abstract
Although their etiologies vary, tumors share a common trait: the control of an oncogenic transcriptional program that is regulated by the interaction of the malignant cells with the stromal and immune cells in the tumor microenvironment (TME). The TME shows high phenotypic and functional heterogeneity that may be modulated by interactions with commensal microbes (the microbiota) both systemically and locally. Unlike host cells, the microbiota adapts after environmental perturbations, impacting host-microbe interactions. In the liver, the bidirectional relationship in the gut and its associated microbiota creates an interdependent environment. Therefore, the gut microbiota and its metabolites modulate liver gene expression directly and indirectly, causing an imbalance in the gut-liver axis, which may result in disease, including carcinogenesis.
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Affiliation(s)
- Maruhen A D Silveira
- Laboratory of Human Carcinogenesis, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA; Centre de Recherche du CHU de Québec - Université Laval, Axe Oncologie, Québec, QC G1V 4G2, Canada; Centre de Recherche sur le Cancer de l'Université Laval, Québec, QC G1R 3S3, Canada
| | - Steve Bilodeau
- Centre de Recherche du CHU de Québec - Université Laval, Axe Oncologie, Québec, QC G1V 4G2, Canada; Centre de Recherche sur le Cancer de l'Université Laval, Québec, QC G1R 3S3, Canada; Centre de Recherche en Données Massives de l'Université Laval, Québec, QC G1V 0A6, Canada; Département de Biologie Moléculaire, Biochimie Médicale et Pathologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Tim F Greten
- Gastrointestinal Malignancy Section, Thoracic and GI Malignancies Branch, Center for Cancer Research, NCI, NIH, Bethesda, MD, USA; NCI-CCR Liver Cancer Program, Center for Cancer Research, NCI, NIH, Bethesda, MD, USA
| | - Xin Wei Wang
- Laboratory of Human Carcinogenesis, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA; NCI-CCR Liver Cancer Program, Center for Cancer Research, NCI, NIH, Bethesda, MD, USA.
| | - Giorgio Trinchieri
- NCI-CCR Liver Cancer Program, Center for Cancer Research, NCI, NIH, Bethesda, MD, USA; Laboratory of Integrative Cancer Immunology, Center for Cancer Research, NCI, NIH, Bethesda, MD, USA.
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23
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Maslennikov R, Ivashkin V, Efremova I, Poluektova E, Kudryavtseva A, Krasnov G. Gut dysbiosis and small intestinal bacterial overgrowth as independent forms of gut microbiota disorders in cirrhosis. World J Gastroenterol 2022; 28:1067-1077. [PMID: 35431497 PMCID: PMC8968519 DOI: 10.3748/wjg.v28.i10.1067] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 06/29/2021] [Accepted: 02/10/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Gut dysbiosis and small intestinal bacterial overgrowth (SIBO) are commonly observed in patients with cirrhosis. Despite the substantial number of articles describing the relations between disorders of gut microbiota and various manifestations of cirrhosis, dysbiosis and SIBO were always studied separately.
AIM To study the relationship of gut dysbiosis and SIBO in cirrhosis.
METHODS This observational study included 47 in-patients with cirrhosis. Stool microbiome was assessed using 16S rRNA gene sequencing. SIBO was assessed using the lactulose hydrogen breath test.
RESULTS SIBO was found in 24/47 (51.1%) patients. Patients with SIBO had a higher abundance of Firmicutes (P = 0.017) and Fusobacteria (P = 0.011), and a lower abundance of Bacteroidetes (P = 0.013) than patients without SIBO. This increase in the abundance of Firmicutes occurred mainly due to an increase in the abundance of bacteria from the genus Blautia (P = 0.020) of the Lachnospiraceae family (P = 0.047), while the abundance of other major families of this phylum [Ruminococcaceae (P = 0.856), Peptostreptococcaceae (P = 0.066), Clostridiaceae (P = 0.463), Eubacteriaceae (P = 0.463), Lactobacillaceae (P = 0.413), and Veillonellaceae (P = 0.632)] did not differ significantly between the patients with and without SIBO. Reduced level of Bacteroidetes in samples from patients with SIBO was a result of the decrease in bacterial numbers from all the major families of this phylum [Bacteroidaceae (P = 0.014), Porphyromonadaceae (P = 0.002), and Rikenellaceae (P = 0.047)], with the exception of Prevotellaceae (P = 0.941). There were no significant differences in the abundance of taxa that were the main biomarkers of cirrhosis-associated gut dysbiosis [Proteobacteria (P = 0.790), Bacilli (P = 0.573), Enterobacteriaceae (P = 0.632), Streptococcaceae (P = 0.170), Staphylococcaceae (P = 0.450), and Enterococcaceae (P = 0.873)] between patients with and without SIBO.
CONCLUSION Despite the differences observed in the gut microbiome between patients with and without SIBO, gut dysbiosis and SIBO are most likely independent disorders of gut microbiota in cirrhosis.
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Affiliation(s)
- Roman Maslennikov
- Department of Internal Medicine, Gastroenterology and Hepatology, Sechenov University, Moscow 119435, Russia
- Scientific Community for Human Microbiome Research, Moscow 119435, Russia
- Department of Internal Medicine 1, Сonsultative and Diagnostic Center 2 of the Moscow City Health Department, Moscow 107564, Russia
| | - Vladimir Ivashkin
- Department of Internal Medicine, Gastroenterology and Hepatology, Sechenov University, Moscow 119435, Russia
- Scientific Community for Human Microbiome Research, Moscow 119435, Russia
| | - Irina Efremova
- Department of Internal Medicine, Gastroenterology and Hepatology, Sechenov University, Moscow 119435, Russia
| | - Elena Poluektova
- Department of Internal Medicine, Gastroenterology and Hepatology, Sechenov University, Moscow 119435, Russia
- Scientific Community for Human Microbiome Research, Moscow 119435, Russia
| | - Anna Kudryavtseva
- Scientific Community for Human Microbiome Research, Moscow 119435, Russia
- Laboratory of Postgenomic Research, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia
| | - George Krasnov
- Laboratory of Postgenomic Research, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia
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24
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Shah A, Holtmann G. Small intestinal bacterial overgrowth in inflammatory bowel disease. Indian J Gastroenterol 2022; 41:23-29. [PMID: 35031976 DOI: 10.1007/s12664-021-01235-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 12/06/2021] [Indexed: 02/04/2023]
Affiliation(s)
- Ayesha Shah
- Faculty of Medicine and Faculty of Health and Behavioral Sciences, The University of Queensland, Brisbane, Australia. .,Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Brisbane, Australia. .,AGIRA (Australian Gastrointestinal Research Alliance) and the NHMRC Centre of Research Excellence in Digestive Health, Brisbane, Australia.
| | - Gerald Holtmann
- Faculty of Medicine and Faculty of Health and Behavioral Sciences, The University of Queensland, Brisbane, Australia.,Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Brisbane, Australia.,AGIRA (Australian Gastrointestinal Research Alliance) and the NHMRC Centre of Research Excellence in Digestive Health, Brisbane, Australia
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25
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Albillos A, Martin-Mateos R, Van der Merwe S, Wiest R, Jalan R, Álvarez-Mon M. Cirrhosis-associated immune dysfunction. Nat Rev Gastroenterol Hepatol 2022; 19:112-134. [PMID: 34703031 DOI: 10.1038/s41575-021-00520-7] [Citation(s) in RCA: 139] [Impact Index Per Article: 69.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/02/2021] [Indexed: 02/08/2023]
Abstract
The term cirrhosis-associated immune dysfunction (CAID) comprises the distinctive spectrum of immune alterations associated with the course of end-stage liver disease. Systemic inflammation and immune deficiency are the key components of CAID. Their severity is highly dynamic and progressive, paralleling cirrhosis stage. CAID involves two different immune phenotypes: the low-grade systemic inflammatory phenotype and the high-grade systemic inflammatory phenotype. The low-grade systemic inflammatory phenotype can be found in patients with compensated disease or clinical decompensation with no organ failure. In this phenotype, there is an exaggerated immune activation but the effector response is not markedly compromised. The high-grade systemic inflammatory phenotype is present in patients with acute-on-chronic liver failure, a clinical situation characterized by decompensation, organ failure and high short-term mortality. Along with high-grade inflammation, this CAID phenotype includes intense immune paralysis that critically increases the risk of infections and worsens prognosis. The intensity of CAID has important consequences on cirrhosis progression and correlates with the severity of liver insufficiency, bacterial translocation and organ failure. Therapies targeting the modulation of the dysfunctional immune response are currently being evaluated in preclinical and clinical studies.
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Affiliation(s)
- Agustín Albillos
- Department of Gastroenterology and Hepatology, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain. .,Departamento de Medicina y Especialidades Médicas, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain. .,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Instituto de Salud Carlos III, Madrid, Spain.
| | - Rosa Martin-Mateos
- Department of Gastroenterology and Hepatology, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.,Departamento de Medicina y Especialidades Médicas, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Instituto de Salud Carlos III, Madrid, Spain
| | - Schalk Van der Merwe
- Laboratory of Hepatology, Department of Chronic Diseases, Metabolism and Aging (CHROMETA), University of Leuven, Leuven, Belgium.,Department of Gastroenterology and Hepatology, University Hospital Gasthuisberg, Leuven, Belgium
| | - Reiner Wiest
- Department of Visceral Surgery and Medicine, University Inselspital, Bern, Switzerland
| | - Rajiv Jalan
- Liver Failure Group, UCL Institute for Liver and Digestive Health, UCL Medical School, Royal Free Hospital, London, UK.,European Foundation for the Study of Chronic Liver Failure, Barcelona, Spain
| | - Melchor Álvarez-Mon
- Departamento de Medicina y Especialidades Médicas, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Instituto de Salud Carlos III, Madrid, Spain.,Department of Internal Medicine, Hospital Universitario Príncipe de Asturias, Alcalá de Henares, Madrid, Spain
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26
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Ghoshal UC, Sachdeva S, Ghoshal U, Misra A, Puri AS, Pratap N, Shah A, Rahman MM, Gwee KA, Tan VPY, Ahmed T, Lee YY, Ramakrishna BS, Talukdar R, Rana SV, Sinha SK, Chen M, Kim N, Holtmann G. Asian-Pacific consensus on small intestinal bacterial overgrowth in gastrointestinal disorders: An initiative of the Indian Neurogastroenterology and Motility Association. Indian J Gastroenterol 2022; 41:483-507. [PMID: 36214973 PMCID: PMC9549446 DOI: 10.1007/s12664-022-01292-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 08/02/2022] [Indexed: 02/04/2023]
Abstract
In the clinical setting, small intestinal bacterial overgrowth (SIBO) is a frequent, but under-diagnosed entity. SIBO is linked to various gastrointestinal (GI) and non-GI disorders with potentially significant morbidity. The optimal management of SIBO is undefined while there is a lack of published consensus guidelines. Against this background, under the auspices of the Indian Neurogastroenterology and Motility Association (INMA), formerly known as the Indian Motility and Functional Diseases Association (IMFDA), experts from the Asian-Pacific region with extensive research and clinical experience in the field of gut dysbiosis including SIBO developed this evidence-based practice guideline for the management of SIBO utilizing a modified Delphi process based upon 37 consensus statements, involving an electronic voting process as well as face-to-face meetings and review of relevant supporting literature. These statements include 6 statements on definition and epidemiology; 11 on etiopathogenesis and pathophysiology; 5 on clinical manifestations, differential diagnosis, and predictors; and 15 on investigations and treatment. When the proportion of those who voted either to accept completely or with minor reservations was 80% or higher, the statement was regarded as accepted. The members of the consensus team consider that this guideline would be valuable to inform clinical practice, teaching, and research on SIBO in the Asian-Pacific region as well as in other countries.
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Affiliation(s)
- Uday C. Ghoshal
- Department of Gastroenterology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226 014 India
| | - Sanjeev Sachdeva
- Department of Gastroenterology, G B Pant Hospital, New Delhi, 110 002 India
| | - Ujjala Ghoshal
- Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226 014 India
| | - Asha Misra
- Department of Gastroenterology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226 014 India
| | | | | | - Ayesha Shah
- University of Queensland, Faculty of Medicine, and Princess Alexandra Hospital, Department of Gastroenterology and Hepatology, Brisbane, Queensland, Australia
| | - M. Masudur Rahman
- Sheikh Russel National Gastroliver Institute and Hospital, Dhaka, Bangladesh
| | - Kok Ann Gwee
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore ,Stomach, Liver and Bowel Centre, Gleneagles Hospital, Singapore, Singapore
| | - Victoria P Y Tan
- Faculty of Medicine, University of Hong Kong, Pok Fu Lam, Hong Kong
| | - Tahmeed Ahmed
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Yeong Yeh Lee
- School of Medical Sciences, Universiti Sains Malaysia, Kota Bharu, Malaysia ,GI Function and Motility Unit, Hospital Universiti Sains Malaysia, Kota Bharu, Malaysia
| | - B S Ramakrishna
- SIMS Institute of Gastroenterology, Hepatology, and Transplantation, SRM Institutes for Medical Science, Chennai, 600 026 India
| | - Rupjyoti Talukdar
- Department of Gastroenterology, Asian Institute of Gastroenterology, Hyderabad, 500 082 India
| | - S V Rana
- Department of Biochemistry, All India Institute of Medical Sciences, Rishikesh, 249 203 India
| | - Saroj K Sinha
- Department of Gastroenterology, Postgraduate Institute of Medical Education and Research, Chandigarh, 160 012 India
| | - Minhu Chen
- Department of Gastroenterology and Hepatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Nayoung Kim
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seoul, South Korea
| | - Gerald Holtmann
- University of Queensland, Faculty of Medicine, and Princess Alexandra Hospital, Department of Gastroenterology and Hepatology, Brisbane, Queensland, Australia
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27
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Philips CA, Augustine P. Gut Barrier and Microbiota in Cirrhosis. J Clin Exp Hepatol 2022; 12:625-638. [PMID: 35535069 PMCID: PMC9077238 DOI: 10.1016/j.jceh.2021.08.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/31/2021] [Indexed: 12/12/2022] Open
Abstract
Gut microbiota and their homeostatic functions are central to the maintenance of the intestinal mucosal barrier. The gut barrier functions as a structural, biological, and immunological barrier, preventing local and systemic invasion and inflammation of pathogenic taxa, resulting in the propagation or causation of organ-specific (liver disease) or systemic diseases (sepsis) in the host. In health, commensal bacteria are involved in regulating pathogenic bacteria, sinister bacterial products, and antigens; and help control and kill pathogenic organisms by secreting antimicrobial metabolites. Gut microbiota also participates in the extraction, synthesis, and absorption of nutrient metabolites, maintains intestinal epithelial integrity and regulates the development, homeostasis, and function of innate and adaptive immune cells. Cirrhosis is associated with local and systemic immune, vascular, and inflammatory changes directly or indirectly linked to perturbations in quality and quantity of intestinal microbiota and intestinal mucosal integrity. Dysbiosis and gut barrier dysfunction are directly involved in the pathogenesis of compensated cirrhosis and the type and severity of complications in decompensated cirrhosis, such as bacterial infections, encephalopathy, extrahepatic organ failure, and progression to acute on chronic liver failure. This paper reviews the normal gut barrier, gut barrier dysfunction, and dysbiosis-associated clinical events in patients with cirrhosis. The role of dietary interventions, antibiotics, prebiotics, probiotics, synbiotics, and healthy donor fecal microbiota transplantation (FMT) to modulate the gut microbiota for improving patient outcomes is further discussed.
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Affiliation(s)
- Cyriac A. Philips
- Department of Translational Hepatology, Monarch Liver Laboratory, The Liver Institute, Center of Excellence in GI Sciences, Rajagiri Hospital, Chunangamvely, Aluva, Ernakulam, Kerala, India,Address for correspondence. Cyriac Abby, The Liver Institute, Center of Excellence in GI Sciences, Ground Floor, Phase II, Rajagiri Hospital, Chunangamvely, Aluva, Ernakulam, Kerala, 683 112, India.
| | - Philip Augustine
- Department of Gastroenterology and Advanced GI Endoscopy, Center of Excellence in GI Sciences, Rajagiri Hospital, Chunangamvely, Aluva, Ernakulam, Kerala, India
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28
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Bi C, Xiao G, Liu C, Yan J, Chen J, Si W, Zhang J, Liu Z. Molecular Immune Mechanism of Intestinal Microbiota and Their Metabolites in the Occurrence and Development of Liver Cancer. Front Cell Dev Biol 2021; 9:702414. [PMID: 34957088 PMCID: PMC8693382 DOI: 10.3389/fcell.2021.702414] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 11/11/2021] [Indexed: 12/12/2022] Open
Abstract
Intestinal microorganisms are closely associated with immunity, metabolism, and inflammation, and play an important role in health and diseases such as inflammatory bowel disease, diabetes, cardiovascular disease, Parkinson’s disease, and cancer. Liver cancer is one of the most fatal cancers in humans. Most of liver cancers are slowly transformed from viral hepatitis, alcoholic liver disease, and non-alcoholic fatty liver disease. However, the relationship between intestinal microbiota and their metabolites, including short-chain fatty acids, bile acids, indoles, and ethanol, and liver cancer remains unclear. Here, we summarize the molecular immune mechanism of intestinal microbiota and their metabolites in the occurrence and development of liver cancer and reveal the important role of the microbiota-gut-liver axis in liver cancer. In addition, we describe how the intestinal flora can be balanced by antibiotics, probiotics, postbiotics, and fecal bacteria transplantation to improve the treatment of liver cancer. This review describes the immunomolecular mechanism of intestinal microbiota and their metabolites in the occurrence and development of hepatic cancer and provides theoretical evidence support for future clinical practice.
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Affiliation(s)
- Chenchen Bi
- Department of Pharmacology, Medical College of Shaoxing University, Shaoxing, China
| | - Geqiong Xiao
- Department of Oncology, Affiliated Hospital of Shaoxing University, Shaoxing, China
| | - Chunyan Liu
- Department of Clinical Medicine, Shaoxing People's Hospital, Shaoxing, China
| | - Junwei Yan
- Department of Pharmacology, Medical College of Shaoxing University, Shaoxing, China
| | - Jiaqi Chen
- Department of Pharmacology, Medical College of Shaoxing University, Shaoxing, China
| | - Wenzhang Si
- Department of General Surgery, Affiliated Hospital of Shaoxing University, Shaoxing, China
| | - Jian Zhang
- Department of Pharmacology, Medical College of Shaoxing University, Shaoxing, China
| | - Zheng Liu
- Department of Pharmacology, Medical College of Shaoxing University, Shaoxing, China
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29
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Xu J, Zhan Q, Fan Y, Lo EKK, Zhang F, Yu Y, El-Nezami H, Zeng Z. Clinical Aspects of Gut Microbiota in Hepatocellular Carcinoma Management. Pathogens 2021; 10:pathogens10070782. [PMID: 34206200 PMCID: PMC8308793 DOI: 10.3390/pathogens10070782] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 06/13/2021] [Accepted: 06/18/2021] [Indexed: 01/02/2023] Open
Abstract
Liver cancer, predominantly hepatocellular carcinoma (HCC), is the third leading cause of cancer-related deaths worldwide. Emerging data highlight the importance of gut homeostasis in the pathogenesis of HCC. Clinical and translational studies revealed the patterns of dysbiosis in HCC patients and their potential role for HCC diagnosis. Research on underlying mechanisms of dysbiosis in HCC development pointed out the direction for improving the treatment and prevention. Despite missing clinical studies, animal models showed that modulation of the gut microbiota by probiotics may become a new way to treat or prevent HCC development.
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Affiliation(s)
- Jinghang Xu
- Department of Infectious Diseases, Peking University First Hospital, Peking University, Beijing 100034, China; (J.X.); (Q.Z.); (Y.F.); (Y.Y.)
| | - Qiao Zhan
- Department of Infectious Diseases, Peking University First Hospital, Peking University, Beijing 100034, China; (J.X.); (Q.Z.); (Y.F.); (Y.Y.)
| | - Yanan Fan
- Department of Infectious Diseases, Peking University First Hospital, Peking University, Beijing 100034, China; (J.X.); (Q.Z.); (Y.F.); (Y.Y.)
| | - Emily Kwun Kwan Lo
- School of Biological Sciences, University of Hong Kong, Pokfulam 999077, Hong Kong, China; (E.K.K.L.); (F.Z.)
| | - Fangfei Zhang
- School of Biological Sciences, University of Hong Kong, Pokfulam 999077, Hong Kong, China; (E.K.K.L.); (F.Z.)
| | - Yanyan Yu
- Department of Infectious Diseases, Peking University First Hospital, Peking University, Beijing 100034, China; (J.X.); (Q.Z.); (Y.F.); (Y.Y.)
| | - Hani El-Nezami
- School of Biological Sciences, University of Hong Kong, Pokfulam 999077, Hong Kong, China; (E.K.K.L.); (F.Z.)
- Institute of Public Health and Clinical Nutrition, School of Medicine, University of Eastern Finland, FI-70211 Kuopio, Finland
- Correspondence: (H.E.-N.); (Z.Z.)
| | - Zheng Zeng
- Department of Infectious Diseases, Peking University First Hospital, Peking University, Beijing 100034, China; (J.X.); (Q.Z.); (Y.F.); (Y.Y.)
- Correspondence: (H.E.-N.); (Z.Z.)
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30
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Ahadi M, Molooghi K, Masoudifar N, Namdar AB, Vossoughinia H, Farzanehfar M. A review of non-alcoholic fatty liver disease in non-obese and lean individuals. J Gastroenterol Hepatol 2021; 36:1497-1507. [PMID: 33217052 DOI: 10.1111/jgh.15353] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 10/26/2020] [Accepted: 11/10/2020] [Indexed: 12/12/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of hepatic disorders. It represents a wide range of chronic liver diseases in patients with no history of significant alcohol consumption, starting with simple steatosis and progressing towards non-alcoholic steatohepatitis, cirrhosis, and ultimately hepatocellular carcinoma. NAFLD is usually associated with type 2 diabetes mellitus, dyslipidemia, metabolic syndrome, and obesity. This disease has mostly been studied in obese individuals; however, it has been widely reported and studied among the lean/non-obese population in recent years. The pathogenesis of NAFLD in non-obese patients is associated with various genetic predispositions, particularly a patatin-like phospholipase domain-containing protein 3 G allele polymorphism, which results in the accumulation of triglyceride in the liver and resistance to insulin. Additionally, dietary factors such as high fructose consumption seem to play a substantial role in the pathology of non-obese NAFLD. Although there is not enough evidence on the treatment of NAFLD in non-obese patients, the standard approach is to advise altering one's lifestyle in order to diminish visceral adiposity. Dietary modification, weight loss, and increased physical activity are highly recommended. We aimed to review and summarize the existing information on the prevalence, pathogenesis, genetic predispositions, diagnosis, and treatment of NAFLD in non-obese patients according to the latest literature.
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Affiliation(s)
- Mitra Ahadi
- Department of Gastroenterology and Hepatology, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Kasra Molooghi
- School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Negin Masoudifar
- School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ali Beheshti Namdar
- Department of Gastroenterology and Hepatology, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hassan Vossoughinia
- Department of Gastroenterology and Hepatology, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohammadreza Farzanehfar
- Department of Gastroenterology and Hepatology, Mashhad University of Medical Sciences, Mashhad, Iran
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31
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Moreno-Gonzalez M, Beraza N. The Role of the Microbiome in Liver Cancer. Cancers (Basel) 2021; 13:2330. [PMID: 34066064 PMCID: PMC8150469 DOI: 10.3390/cancers13102330] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 04/30/2021] [Accepted: 05/03/2021] [Indexed: 12/11/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is the most common malignancy occuring in the context of chronic liver disease and is one of the main causes of cancer-derived death worldwide. The lack of effective treatments, together with the poor prognosis, underlines the urge to develop novel and multidisciplinary therapeutics. An increasing body of evidence shows that HCC associates with changes in intestinal microbiota abundance and composition as well as with impaired barrier function, leading to the release of bacteria and their metabolites to the liver. These factors trigger a cascade of inflammatory responses contributing to liver cirrhosis and constituting an ideal environment for the progression of HCC. Interestingly, the use of bacteriotherapy in human and preclinical studies of chronic liver disease and HCC has been shown to successfully modify the microbiota composition, reducing overall inflammation and fibrosis. In this review, we explore the existing knowledge on the characterisation of the intestinal microbial composition in humans and experimental murine chronic liver disease and HCC, as well as the use of antibiotics and bacteriotherapy as therapeutic options.
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Affiliation(s)
- Mar Moreno-Gonzalez
- Gut Microbes and Health Institute Strategic Programme, Quadram Institute Bioscience, Norwich Research Park, Norwich NR4 7UQ, UK;
| | - Naiara Beraza
- Gut Microbes and Health Institute Strategic Programme, Quadram Institute Bioscience, Norwich Research Park, Norwich NR4 7UQ, UK;
- Food Innovation and Health Institute Strategic Programme, Quadram Institute Bioscience, Norwich Research Park, Norwich NR4 7UQ, UK
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Small Intestinal Bacterial Overgrowth in Functional Dyspepsia: A Systematic Review and Meta-Analysis. Am J Gastroenterol 2021; 116:935-942. [PMID: 33734110 DOI: 10.14309/ajg.0000000000001197] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Accepted: 01/22/2021] [Indexed: 12/11/2022]
Abstract
INTRODUCTION This systematic review and meta-analysis aimed to determine the role of small intestinal bacterial overgrowth (SIBO) in patients with functional dyspepsia (FD). METHODS Electronic databases were searched until July 2020 for studies reporting prevalence of SIBO in FD. The prevalence rates, odds ratio, and 95% confidence intervals (CIs) of SIBO in FD and controls were calculated. RESULTS Seven studies with 263 patients with FD and 84 controls were identified. The odds for SIBO in patients with FD were significantly higher as compared to that in controls (odds ratio = 4.3, 95% CI, 1.1-17.5, 4 studies, 234 participants); however, there was moderate heterogeneity in this analysis. Including high-quality, case-control studies (all using glucose breath tests [GBTs]), the risk of SIBO in patients with FD as compared to controls was 2.8 higher (95% CI 0.8-10.0, 3 studies, 200 participants) with minimal heterogeneity in this analysis. Using the lactulose breath test, SIBO prevalence in FD was significantly higher (53.4%, 95% CI 33.9-71.9, 3 studies, 110 participants) as compared to that with GBT (17.2%, 95% CI 8.6-31.6, 4 studies, 153 participants). Substantial heterogeneity was found in studies using the lactulose breath test but not in studies using GBT. There was no significant difference in SIBO prevalence in patients with FD according to FD subtype. DISCUSSION This meta-analysis suggests a link between FD and SIBO. The quality of evidence is low and can be largely attributed to the type of breath test for SIBO diagnosis and clinical heterogeneity. More appropriately designed studies are required to confirm the link between SIBO and FD.
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The systemic inflammation hypothesis: Towards a new paradigm of acute decompensation and multiorgan failure in cirrhosis. J Hepatol 2021; 74:670-685. [PMID: 33301825 DOI: 10.1016/j.jhep.2020.11.048] [Citation(s) in RCA: 208] [Impact Index Per Article: 69.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 11/24/2020] [Accepted: 11/30/2020] [Indexed: 12/11/2022]
Abstract
Acute decompensation (AD) of cirrhosis is defined by the development of ascites, hepatic encephalopathy and/or variceal bleeding. Ascites is traditionally attributed to splanchnic arterial vasodilation and left ventricular dysfunction, hepatic encephalopathy to hyperammonaemia, and variceal haemorrhage to portal hypertension. Recent large-scale European observational studies have shown that systemic inflammation is a hallmark of AD. Here we present a working hypothesis, the systemic inflammation hypothesis, suggesting that systemic inflammation through an impairment of the functions of one or more of the major organ systems may be a common theme and act synergistically with the traditional mechanisms involved in the development of AD. Systemic inflammation may impair organ system function through mechanisms which are not mutually exclusive. The first mechanism is a nitric oxide-mediated accentuation of the preexisting splanchnic vasodilation, resulting in the overactivation of the endogenous vasoconstrictor systems which elicit intense vasoconstriction and hypoperfusion in certain vascular beds, in particular the renal circulation. Second, systemic inflammation may cause immune-mediated tissue damage, a process called immunopathology. Finally, systemic inflammation may induce important metabolic changes. Indeed, systemic inflammatory responses are energetically expensive processes, requiring reallocation of nutrients (glucose, amino acids and lipids) to fuel immune activation. Systemic inflammation also inhibits nutrient consumption in peripheral (non-immune) organs, an effect that may provide one mechanism of reallocation and prioritisation of metabolic fuels for inflammatory responses. However, the decrease in nutrient consumption in peripheral organs may result in decreased mitochondrial production of ATP (energy) and subsequently impaired organ function.
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Fan Y, Li Y, Chu Y, Liu J, Cui L, Zhang D. Toll-Like Receptors Recognize Intestinal Microbes in Liver Cirrhosis. Front Immunol 2021; 12:608498. [PMID: 33708204 PMCID: PMC7940369 DOI: 10.3389/fimmu.2021.608498] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Accepted: 01/11/2021] [Indexed: 12/15/2022] Open
Abstract
Liver cirrhosis is one major cause of mortality in the clinic, and treatment of this disease is an arduous task. The scenario will be even getting worse with increasing alcohol consumption and obesity in the current lifestyle. To date, we have no medicines to cure cirrhosis. Although many etiologies are associated with cirrhosis, abnormal intestinal microbe flora (termed dysbiosis) is a common feature in cirrhosis regardless of the causes. Toll-like receptors (TLRs), one evolutional conserved family of pattern recognition receptors in the innate immune systems, play a central role in maintaining the homeostasis of intestinal microbiota and inducing immune responses by recognizing both commensal and pathogenic microbes. Remarkably, recent studies found that correction of intestinal flora imbalance could change the progress of liver cirrhosis. Therefore, correction of intestinal dysbiosis and targeting TLRs can provide novel and promising strategies in the treatment of liver cirrhosis. Here we summarize the recent advances in the related topics. Investigating the relationship among innate immunity TLRs, intestinal flora disorders, and liver cirrhosis and exploring the underlying regulatory mechanisms will assuredly have a bright future for both basic and clinical research.
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Affiliation(s)
- Yujing Fan
- Department of Gastroenterology and Hepatology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Yunpeng Li
- Department of Gastroenterology and Hepatology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Yanjie Chu
- Department of Gastroenterology and Hepatology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Jing Liu
- Department of Gastroenterology and Hepatology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Lin Cui
- Department of Gastroenterology and Hepatology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Dekai Zhang
- Center for Infectious and Inflammatory Diseases, Texas A&M University, Houston, TX, United States
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Hassouneh R, Bajaj JS. Gut Microbiota Modulation and Fecal Transplantation: An Overview on Innovative Strategies for Hepatic Encephalopathy Treatment. J Clin Med 2021; 10:330. [PMID: 33477417 PMCID: PMC7830387 DOI: 10.3390/jcm10020330] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/07/2021] [Accepted: 01/09/2021] [Indexed: 02/06/2023] Open
Abstract
Hepatic encephalopathy (HE) is a major complication of cirrhosis, which is associated with gut microbial composition and functional alterations. Current treatments largely focus on gut microbiota using lactulose, rifaximin and other agents. However, despite these treatments, patients with HE have a high rate of readmission, morbidity and cognitive impairment. Fecal microbiota transplant (FMT) involves introduction of a donor microbiota into a recipient and is currently mainly used for recurrent C. difficile infection (rCDI). The role of FMT in cirrhosis and HE is evolving. There have been two randomized clinical trials (RCT) and several case reports/series in cirrhosis. Both RCTs were safety-focused phase 1 trials. One involved pre-FMT antibiotics and FMT enema versus standard of care, while the other involved 15 FMT capsules versus placebo without pre-FMT antibiotics. There was evidence of safety in both trials and the FMT group demonstrated reduction in hospitalizations compared to the non-FMT group. Changes in microbial function centered around short-chain fatty acids, bile acids and brain function showed improvement in the FMT groups. Long-term follow-up demonstrated continued safety and reduction in the antibiotic-resistance gene carriage. However, larger trials of FMT in HE are needed that can refine the dose, duration and route of FMT administration.
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Affiliation(s)
- Ramzi Hassouneh
- Department of Internal Medicine, Virginia Commonwealth University Medical Center, Richmond, VA 23298, USA;
| | - Jasmohan S. Bajaj
- Division of Gastroenterology, Hepatology and Nutrition Virginia Commonwealth University and Central Virginia Veterans Healthcare System, 1201 Broad Rock Blvd, Richmond, VA 23249, USA
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Lira MMP, de Medeiros Filho JEM, Baccin Martins VJ, da Silva G, de Oliveira Junior FA, de Almeida Filho ÉJB, Silva AS, Henrique da Costa-Silva J, de Brito Alves JL. Association of worsening of nonalcoholic fatty liver disease with cardiometabolic function and intestinal bacterial overgrowth: A cross-sectional study. PLoS One 2020; 15:e0237360. [PMID: 32845887 PMCID: PMC7449384 DOI: 10.1371/journal.pone.0237360] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 07/23/2020] [Indexed: 12/15/2022] Open
Abstract
Background & aims Non-alcoholic fatty liver disease (NAFLD) has been associated with small bowel bacterial overgrowth (SIBO) and cardiometabolic dysfunction. This cross-sectional study aimed to evaluate the cardio-metabolic parameters and SIBO in patients with different degrees of hepatic fibrosis estimated by NAFLD fibrosis score (NFS). Methods Subjects (n = 78) were allocated to three groups: Healthy control (n = 30), NAFLD with low risk of advanced fibrosis (NAFLD-LRAF, n = 17) and NAFLD with a high risk of advanced fibrosis (NAFLD-HRAF, n = 31). Anthropometrics, blood pressure, electrocardiogram and heart rate variability (HRV) were evaluated. Only the NAFLD-LRAF and NAFLD-HRAF groups were submitted to blood biochemical analysis and glucose hydrogen breath tests. Results The NAFLD-HRAF group had higher age and body mass index when compared to the control and NAFLD-LRAF groups. The prevalence of SIBO in the NAFLD group was 8.33%. The low frequency/high-frequency ratio (LF/HF ratio) was augmented in NAFLD-LRAF (p < 0.05) when compared with control group. NAFLD-HRAF group had a wide QRS complex (p < 0.05) and reduced LF/HF ratio (p < 0.05) compared to the control and NAFLD-LRAF groups. Serum levels of albumin and platelets were more reduced in the NAFLD-HRAF subjects (p < 0.05) than in the NAFLD-LRAF. Conclusions NAFLD impairs cardiac autonomic function. Greater impairment was found in subjects with a worse degree of hepatic fibrosis estimated by NFS. Hypoalbuminemia and thrombocytopenia were higher in subjects with a worse degree of hepatic fibrosis, whereas prevalence of SIBO positive was similar between the groups.
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Affiliation(s)
- Marília Marques Pereira Lira
- Department of Nutrition, Health Sciences Center, Federal University of Paraiba, João Pessoa, Brazil
- Department of Internal Medicine, Medical Sciences Center, Federal University of Paraiba, João Pessoa, Brazil
- Lauro Wanderley Hospital, Federal University of Paraiba, João Pessoa, Brazil
| | - José Eymard Moraes de Medeiros Filho
- Department of Internal Medicine, Medical Sciences Center, Federal University of Paraiba, João Pessoa, Brazil
- Lauro Wanderley Hospital, Federal University of Paraiba, João Pessoa, Brazil
| | - Vinícius José Baccin Martins
- Department of Physiology and Pathology, Health Sciences Center, Federal University of Paraiba, João Pessoa, Brazil
| | - Gitana da Silva
- Lauro Wanderley Hospital, Federal University of Paraiba, João Pessoa, Brazil
| | | | | | - Alexandre Sérgio Silva
- Department of Physical Education, Health Sciences Center, Federal University of Paraiba, João Pessoa, Brazil
| | - João Henrique da Costa-Silva
- Department of Physical Education and Sport Sciences, Federal University of Pernambuco, Vitória de Santo Antão, PE, Brazil
| | - José Luiz de Brito Alves
- Department of Nutrition, Health Sciences Center, Federal University of Paraiba, João Pessoa, Brazil
- * E-mail: ,
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Dysbiosis of the Duodenal Mucosal Microbiota Is Associated With Increased Small Intestinal Permeability in Chronic Liver Disease. Clin Transl Gastroenterol 2020; 10:e00068. [PMID: 31373933 PMCID: PMC6736223 DOI: 10.14309/ctg.0000000000000068] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Chronic liver disease (CLD) is associated with both alterations of the stool microbiota and increased small intestinal permeability. However, little is known about the role of the small intestinal mucosa-associated microbiota (MAM) in CLD. The aim of this study was to evaluate the relationship between the duodenal MAM and both small intestinal permeability and liver disease severity in CLD.
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Shah A, Talley NJ, Koloski N, Macdonald GA, Kendall BJ, Shanahan ER, Walker MM, Keely S, Jones MP, Morrison M, Holtmann GJ. Duodenal bacterial load as determined by quantitative polymerase chain reaction in asymptomatic controls, functional gastrointestinal disorders and inflammatory bowel disease. Aliment Pharmacol Ther 2020; 52:155-167. [PMID: 32412673 DOI: 10.1111/apt.15786] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 02/12/2020] [Accepted: 04/20/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Small intestinal bacterial overgrowth may play a role in gastrointestinal and non-gastrointestinal diseases. AIMS To use quantitative polymerase chain reaction (qPCR) to determine and compare bacterial loads of duodenal biopsies in asymptomatic controls, and patients with functional gastrointestinal disorders (FGIDs) and inflammatory bowel disease (IBD) including ulcerative colitis (UC) and Crohn's disease (CD). To define effects of gastric acid inhibition on bacterial load, explore links of bacterial load and gastrointestinal symptoms in response to a standardised nutrient challenge and compare bacterial load with glucose breath test results. METHODS In 237 patients (63 controls, 84 FGID and 90 IBD), we collected mucosal samples under aseptic conditions during endoscopy extracted and total DNA. Bacterial load metric was calculated utilising qPCR measurements of the bacterial 16S rRNA gene, normalised to human beta-actin expression. Standard glucose breath test and nutrient challenge test were performed. RESULTS The duodenal microbial load was higher in patients with FGID (0.22 ± 0.03) than controls (0.07 ± 0.05; P = 0.007) and patients with UC (0.01 ± 0.05) or CD (0.02 ± 0.09), (P = 0.0001). While patients treated with proton pump inhibitors (PPI) had significantly higher bacterial loads than non-users (P < 0.05), this did not explain differences between patient groups and controls. Bacterial load was significantly (r = 0.21, P < 0.016) associated with the symptom response to standardised nutrient challenge test. Methane, but not hydrogen values on glucose breath test were associated with bacterial load measured utilising qPCR. CONCLUSIONS Utilising qPCR, a diagnosis of FGID and treatment with PPI were independently associated with increased bacterial loads. Increased bacterial loads are associated with an augmented symptom response to a standardised nutrient challenge.
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Affiliation(s)
- Ayesha Shah
- Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Brisbane, Qld, Australia.,Faculty of Medicine and Faulty of Health and Behavioural Sciences, University of Queensland, Brisbane, Qld, Australia
| | - Nicholas J Talley
- Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia
| | - Natasha Koloski
- Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Brisbane, Qld, Australia.,Faculty of Medicine and Faulty of Health and Behavioural Sciences, University of Queensland, Brisbane, Qld, Australia
| | - Graeme A Macdonald
- Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Brisbane, Qld, Australia.,Faculty of Medicine and Faulty of Health and Behavioural Sciences, University of Queensland, Brisbane, Qld, Australia
| | - Bradley J Kendall
- Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Brisbane, Qld, Australia.,Faculty of Medicine and Faulty of Health and Behavioural Sciences, University of Queensland, Brisbane, Qld, Australia
| | - Erin R Shanahan
- Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Brisbane, Qld, Australia.,Faculty of Medicine and Faulty of Health and Behavioural Sciences, University of Queensland, Brisbane, Qld, Australia
| | - Marjorie M Walker
- Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia
| | - Simon Keely
- Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia
| | - Michael P Jones
- Psychology Department, Macquarie University, Ryde, NSW, Australia
| | - Mark Morrison
- Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Brisbane, Qld, Australia.,Diamantina Institute, University of Queensland, Brisbane, Qld, Australia
| | - Gerald J Holtmann
- Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Brisbane, Qld, Australia.,Faculty of Medicine and Faulty of Health and Behavioural Sciences, University of Queensland, Brisbane, Qld, Australia
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Abstract
Primary sclerosing cholangitis (PSC) is a rare, immune-mediated, chronic cholestatic liver disease associated with a unique phenotype of inflammatory bowel disease that frequently manifests as pancolitis with right-sided predominance. Available data suggest a bidirectional interplay of the gut-liver axis with critical roles for the gastrointestinal microbiome and circulating bile acids (BAs) in the pathophysiology of PSC. BAs shape the gut microbiome, whereas gut microbes have the potential to alter BAs, and there are emerging data that alterations of BAs and the microbiome are not simply a consequence but the cause of PSC. Clustering of PSC in families may suggest that PSC occurs in genetically susceptible individuals. After exposure to an environmental trigger (e.g., microbial byproducts or BAs), an aberrant or exaggerated cholangiocyte-induced immune cascade occurs, ultimately leading to bile duct damage and progressive fibrosis. The pathophysiology can be conceptualized as a triad of (1) gut dysbiosis, (2) altered BA metabolism, and (3) immune-mediated biliary injury. Immune activation seems to be central to the disease process, but immunosuppression does not improve clinical outcomes or alter the natural history of PSC. Currently, orthoptic liver transplantation is the only established life-saving treatment, whereas antimicrobial therapy or fecal transplantation is an emerging therapeutic option for PSC. The beneficial effects of these microbiome-based therapies are likely mediated by a shift of the gut microbiome with favorable effects on BA metabolism. In the future, personalized approaches will allow to better target the interdependence between microbiome, immune function, and BA metabolism and potentially cure patients with PSC.
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Albillos A, de Gottardi A, Rescigno M. The gut-liver axis in liver disease: Pathophysiological basis for therapy. J Hepatol 2020; 72:558-577. [PMID: 31622696 DOI: 10.1016/j.jhep.2019.10.003] [Citation(s) in RCA: 961] [Impact Index Per Article: 240.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 09/14/2019] [Accepted: 10/02/2019] [Indexed: 02/06/2023]
Abstract
The gut-liver axis refers to the bidirectional relationship between the gut and its microbiota, and the liver, resulting from the integration of signals generated by dietary, genetic and environmental factors. This reciprocal interaction is established by the portal vein which enables transport of gut-derived products directly to the liver, and the liver feedback route of bile and antibody secretion to the intestine. The intestinal mucosal and vascular barrier is the functional and anatomical structure that serves as a playground for the interactions between the gut and the liver, limiting the systemic dissemination of microbes and toxins while allowing nutrients to access the circulation and to reach the liver. The control of microbial communities is critical to maintaining homeostasis of the gut-liver axis, and as part of this bidirectional communication the liver shapes intestinal microbial communities. Alcohol disrupts the gut-liver axis at multiple interconnected levels, including the gut microbiome, mucus barrier, epithelial barrier and at the level of antimicrobial peptide production, which increases microbial exposure and the proinflammatory environment of the liver. Growing evidence indicates the pathogenetic role of microbe-derived metabolites, such as trimethylamine, secondary bile acids, short-chain fatty acids and ethanol, in the pathogenesis of non-alcoholic fatty liver disease. Cirrhosis by itself is associated with profound alterations in gut microbiota and damage at the different levels of defence of the intestinal barrier, including the epithelial, vascular and immune barriers. The relevance of the severe disturbance of the intestinal barrier in cirrhosis has been linked to translocation of live bacteria, bacterial infections and disease progression. The identification of the elements of the gut-liver axis primarily damaged in each chronic liver disease offers possibilities for intervention. Beyond antibiotics, upcoming therapies centred on the gut include new generations of probiotics, bacterial metabolites (postbiotics), faecal microbial transplantation, and carbon nanoparticles. FXR-agonists target both the gut and the liver and are currently being tested in different liver diseases. Finally, synthetic biotic medicines, phages that target specific bacteria or therapies that create physical barriers between the gut and the liver offer new therapeutic approaches.
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Affiliation(s)
- Agustín Albillos
- Servicio de Gastroenterología y Hepatología, Hospital Universitario Ramón y Cajal, Universidad de Alcalá, IRYCIS, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Instituto de Salud Carlos III, Madrid, Spain.
| | - Andrea de Gottardi
- Hepatology, Inselspital and Department of Biomedical Research, University of Bern, Switzerland; Servizio di Gastroenterología e Epatologia, Ente Ospedaliero Cantonale, Università della Svizzera Italiana, Lugano, Switzerland
| | - María Rescigno
- Department of Biomedical Sciences, Humanitas University, 20090 Pieve Emanuele (Mi), Italy; Humanitas Clinical and Research Center, IRCCS, 20089 Rozzano (Mi), Italy
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Advances in Gut Microbiota of Viral Hepatitis Cirrhosis. BIOMED RESEARCH INTERNATIONAL 2019; 2019:9726786. [PMID: 31886272 PMCID: PMC6893240 DOI: 10.1155/2019/9726786] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 10/28/2019] [Accepted: 11/04/2019] [Indexed: 02/06/2023]
Abstract
Although gut dysbiosis appears in 20%-75% of cirrhotic patients, there are limited data on microbiota profiles in viral hepatitis cirrhotics and its role in progression to cirrhosis. Further understanding on the relationship between gut dysbiosis and cirrhosis presents a unique opportunity in not only predicting the development of cirrhosis but also discovering new therapies. Recent advances have been made on identifying unique microbiota in viral hepatitis cirrhotics and adopting the microbiota index to predict cirrhosis. Therapeutic intervention with microbiome-modulating has been explored. Cirrhosis from viral infection has unique bacterial or fungal profiles, which include increased numbers of Prevotella, Streptococcus, Staphylococcaceae, and Enterococcus, as well as decreased Ruminococcus and Clostridium. In addition, the gut microbiota can stimulate liver immunity, effectively helping hepatitis virus clearance. In clinical settings, CDR, GDI, Basidiomycota/Ascomycota, specific POD, and so forth are efficient microbiota indexes to diagnose or prognosticate cirrhosis from viral hepatitis. FMT, probiotics, and prebiotics can restore microbial diversity in cirrhotic patients with viral hepatitis, decrease ammonia serum or endotoxemia levels, prevent complications, reduce rehospitalization rate, and improve prognosis. Cirrhotics from viral hepatitis had unique bacterial or fungal profiles, associated with specific metabolic, immune, and endocrinological statuses. Such profiles are modifiable with medical treatment. The role of gut archaea and virome, implementation of FMT, microbiota metabolites as adjuvant immunotherapy, and microbiota indexes for prognostication deserve attention.
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Maslennikov R, Pavlov C, Ivashkin V. Is small intestinal bacterial overgrowth a cause of hyperdynamic circulation in cirrhosis? THE TURKISH JOURNAL OF GASTROENTEROLOGY : THE OFFICIAL JOURNAL OF TURKISH SOCIETY OF GASTROENTEROLOGY 2019; 30:964-975. [PMID: 31767551 PMCID: PMC6883995 DOI: 10.5152/tjg.2019.18551] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND/AIMS Small intestinal bacterial overgrowth (SIBO) and hemodynamic changes are common in cirrhosis. We wanted to examine our hypothesis whether SIBO leads to hemodynamic changes in cirrhosis. MATERIALS AND METHODS A total of 50 patients with cirrhosis and 15 healthy controls were enrolled in a pilot prospective study. All participants underwent the lactulose hydrogen breath test for SIBO and echocardiography with a simultaneous assessment of blood pressure and heart rate. Cardiac output and systemic vascular resistance were calculated. RESULTS Study participants with SIBO had a lower systolic blood pressure and systemic vascular resistance compared to those without SIBO and to healthy controls (110.2±12.3 mmHg vs. 126.2±21.0 mmHg and 121.2±9.8 mmHg; p=0.005 and p=0.011, respectively; 1312±352 dyn•s•cm-5 vs. 1704±424 dyn•s•cm-5 and 1648±272 dyn•s•cm-5; p=0.001 and p=0.006, respectively), but a higher cardiac output (5.38±1.41 l/min vs. 4.52±1.03 l/min and 4.40±0.68 l/min; p=0.034 and p=0.041, respectively) and C-reactive protein (10.5[1.2-16.5] mg/l vs. 2.8[0.6-9.1] mg/l; p=0.028; no comparison with healthy controls). There were no significant differences between patients without SIBO and healthy controls with regard to systolic blood pressure (p=0.554), systemic vascular resistance (p=0.874), and cardiac output (p=0.795). SIBO was associated with vasodilation and hyperdynamic circulation in decompensated cirrhosis (p=0.002; p=0.012), but not in compensated cirrhosis (p=1.000; p=0.474). CONCLUSIONS SIBO is associated with hyperdynamic circulation and other hemodynamic changes in cirrhosis and may be a principal factor causing these through systemic inflammation.
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Affiliation(s)
- Roman Maslennikov
- Department of Gastroenterology and Hepatology, Sechenov University, Moscow, Russia
| | - Chavdar Pavlov
- Department of Gastroenterology and Hepatology, Sechenov University, Moscow, Russia
| | - Vladimir Ivashkin
- Department of Gastroenterology and Hepatology, Sechenov University, Moscow, Russia
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Campion D, Giovo I, Ponzo P, Saracco GM, Balzola F, Alessandria C. Dietary approach and gut microbiota modulation for chronic hepatic encephalopathy in cirrhosis. World J Hepatol 2019; 11:489-512. [PMID: 31293718 PMCID: PMC6603507 DOI: 10.4254/wjh.v11.i6.489] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 05/15/2019] [Accepted: 05/20/2019] [Indexed: 02/06/2023] Open
Abstract
Hepatic encephalopathy (HE) is a common and serious neuropsychiatric complication of cirrhosis, acute liver failure, and porto-systemic shunting. HE largely contributes to the morbidity of patients with liver disease, severely affecting the quality of life of both patients and their relatives and being associated with poor prognosis. Its presentation is largely variable, manifesting with a broad spectrum of cognitive abnormalities ranging from subtle cognitive impairment to coma. The pathogenesis of HE is complex and has historically been linked with hyperammonemia. However, in the last years, it has become evident that the interplay of multiple actors, such as intestinal dysbiosis, gut hyperpermeability, and neuroinflammation, is of crucial importance in its genesis. Therefore, HE can be considered a result of a dysregulated gut-liver-brain axis function, where cognitive impairment can be reversed or prevented by the beneficial effects induced by "gut-centric" therapies, such as non-absorbable disaccharides, non-absorbable antibiotics, probiotics, prebiotics, and fecal microbiota transplantation. In this context dietary modifications, by modulating the intestinal milieu, can also provide significant benefit to cirrhotic patients with HE. This review will provide a comprehensive insight into the mechanisms responsible for gut-liver-brain axis dysregulation leading to HE in cirrhosis. Furthermore, it will explore the currently available therapies and the most promising future treatments for the management of patients with HE, with a special focus on the dietary approach.
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Affiliation(s)
- Daniela Campion
- Division of Gastroenterology and Hepatology, Città della Salute e della Scienza di Torino Hospital, University of Turin, 10126 Turin, Italy
| | - Ilaria Giovo
- Division of Gastroenterology and Hepatology, Città della Salute e della Scienza di Torino Hospital, University of Turin, 10126 Turin, Italy
| | - Paola Ponzo
- Division of Gastroenterology and Hepatology, Città della Salute e della Scienza di Torino Hospital, University of Turin, 10126 Turin, Italy
| | - Giorgio M Saracco
- Division of Gastroenterology and Hepatology, Città della Salute e della Scienza di Torino Hospital, University of Turin, 10126 Turin, Italy
| | - Federico Balzola
- Division of Gastroenterology and Hepatology, Città della Salute e della Scienza di Torino Hospital, University of Turin, 10126 Turin, Italy
| | - Carlo Alessandria
- Division of Gastroenterology and Hepatology, Città della Salute e della Scienza di Torino Hospital, University of Turin, 10126 Turin, Italy.
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Abstract
PURPOSE OF REVIEW To critically review recent (past 3 years) literature on the definition, diagnosis, and management of small intestinal bacterial overgrowth (SIBO). RECENT FINDINGS While various series continue to illustrate the occurrence of SIBO in disease states where well-known risk factors for its occurrence are present (hypochlorhydria, disorders of intestinal structure or motor function, pancreatic insufficiency, and chronic liver disease, for example), the current challenge is in defining the limits of SIBO. Is SIBO truly common among those with "functional" gastrointestinal symptoms where there is no evidence of maldigestion or malabsorption; the original hallmarks of SIBO? Our attempts to address this question continue to be hampered by the limitations of our diagnostic tool kit. There is hope-the application of modern molecular techniques to the study of the small intestinal microbiome, together with some innovative sampling techniques, such as real-time intestinal gas sampling, may soon allow us to truly define the spectrum of SIBO. SIBO, once removed from its original confines as a cause of malabsorption syndrome, has proven to be an elusive and moving target. Only the most rigorous studies employing validated methodologies will finally corral this mysterious entity.
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Affiliation(s)
- Eamonn M M Quigley
- Lynda K and David M Underwood Center for Digestive Disorders, Division of Gastroenterology and Hepatology, Houston Methodist Hospital, Weill Cornell Medical College, Houston, TX, USA.
- Houston Methodist Gastroenterology Associates, 6550 Fannin St, SM 1201, Houston, TX, 77030, USA.
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Maslennikov R, Pavlov C, Ivashkin V. Small intestinal bacterial overgrowth in cirrhosis: systematic review and meta-analysis. Hepatol Int 2018; 12:567-576. [PMID: 30284684 DOI: 10.1007/s12072-018-9898-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 09/19/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND Small intestinal bacterial overgrowth (SIBO) was detected in cirrhosis in many studies. The aim is to perform a systematic review and meta-analysis on the prevalence of SIBO in cirrhosis and on the relationship of SIBO with features of cirrhosis. METHODS PUBMED search (until 14 January 2018) was performed. Specific search terms were: '(cirrhosis) AND (SIBO OR bacterial overgrowth)'. Studies not relating to cirrhosis or SIBO, animal studies, and non-original articles were excluded. A meta-analysis of all studies was performed using a random-effects model. RESULTS 117 references were identified by the PUBMED search. 3 references were added after handsearching the reference lists of all the articles. 99 references were excluded. 21 studies (included in total 1264 cirrhotics and 306 controls) remained for qualitative analysis and quantitative synthesis. Prevalence of SIBO for cirrhosis was 40.8% (95% CI 34.8-47.1), while the prevalence of SIBO for controls was 10.7% (95% CI 5.7-19.0). OR 6.83 (95% CI 4.16-11.21; p < 0.001). Prevalence of SIBO for decompensated cirrhosis was higher than prevalence of SIBO for compensated cirrhosis (50.5% vs. 31.2%; p < 0.001). SIBO in cirrhosis was associated with ascites (p < 0.001), minimal hepatic encephalopathy (p = 0.001), bacterial translocation (p = 0.026), spontaneous bacterial peritonitis (p = 0.008), prolonged orocecal transit time (p < 0.001), and was not associated with hypocoagulation. Further studies are required to clarify the relationship of SIBO with hyperbilirubinemia, hypoalbuminemia, overt hepatic encephalopathy in past, esophageal varices and systemic inflammation. CONCLUSION Small intestinal bacterial overgrowth is more often detected in cirrhosis than in healthy persons and is associated with some features of cirrhosis.
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Affiliation(s)
- Roman Maslennikov
- Sechenov University, Pogodinskaya Str., 1, bld. 1, 119435, Moscow, Russian Federation.
| | - Chavdar Pavlov
- Sechenov University, Pogodinskaya Str., 1, bld. 1, 119435, Moscow, Russian Federation
| | - Vladimir Ivashkin
- Sechenov University, Pogodinskaya Str., 1, bld. 1, 119435, Moscow, Russian Federation
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Konturek PC, Harsch IA, Konturek K, Schink M, Konturek T, Neurath MF, Zopf Y. Gut⁻Liver Axis: How Do Gut Bacteria Influence the Liver? Med Sci (Basel) 2018; 6:medsci6030079. [PMID: 30227645 PMCID: PMC6165386 DOI: 10.3390/medsci6030079] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 09/09/2018] [Accepted: 09/10/2018] [Indexed: 12/16/2022] Open
Abstract
Chronic liver diseases are a major cause of morbidity and mortality worldwide. Recently, gut dysbiosis was identified as an important factor in the pathogenesis of liver diseases. The relationship between gut microbiota and the liver is still not well understood; however, dysfunction of the gut mucosal barrier ("leaky gut") and increased bacterial translocation into the liver via the gut⁻liver axis probably play crucial roles in liver disease development and progression. The liver is an important immunological organ, and, after exposure to gut-derived bacteria via portal circulation, it responds with activation of the innate and adaptive immune system, leading to hepatic injury. A better understanding of the pathophysiological links among gut dysbiosis, the integrity of the gut barrier, and the hepatic immune response to gut-derived factors is essential for the development of new therapies to treat chronic liver diseases.
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Affiliation(s)
- Peter Christopher Konturek
- Department of Internal Medicine 2nd, Thuringia-Clinic Saalfeld, Teaching Hospital of the University of Jena, 68, D-07318 Jena, Germany.
| | - Igor Alexander Harsch
- Department of Internal Medicine 2nd, Thuringia-Clinic Saalfeld, Teaching Hospital of the University of Jena, 68, D-07318 Jena, Germany.
| | - Kathrin Konturek
- Department of Internal Medicine 2nd, Thuringia-Clinic Saalfeld, Teaching Hospital of the University of Jena, 68, D-07318 Jena, Germany.
| | - Monic Schink
- 1st Department of Internal Medicine, University Erlangen-Nuremberg, 91054 Erlangen, Germany.
| | - Thomas Konturek
- Department of Medicine, St. Elizabeth's Medical Center, Tufts University School of Medicine, Boston, MA 02135, USA.
| | - Markus F Neurath
- 1st Department of Internal Medicine, University Erlangen-Nuremberg, 91054 Erlangen, Germany.
| | - Yurdaguel Zopf
- 1st Department of Internal Medicine, University Erlangen-Nuremberg, 91054 Erlangen, Germany.
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