Fecal Microbiota Transplantation Is Safe and Effective in Patients With Clostridioides difficile Infection and Cirrhosis

From chaos to order: optimizing fecal microbiota transplantation for enhanced immune checkpoint inhibitors efficacy

The integration of fecal microbiota transplantation (FMT) with immune checkpoint inhibitors (ICIs) presents a promising approach for enhancing cancer treatment efficacy and overcoming therapeutic resistance. This review critically examines the controversial effects of FMT on ICIs outcomes and elucidates the underlying mechanisms. We investigate how FMT modulates gut microbiota composition, microbial metabolite profiles, and the tumor microenvironment, thereby influencing ICIs effectiveness. Key factors influencing FMT efficacy, including donor selection criteria, recipient characteristics, and administration protocols, are comprehensively discussed. The review delineates strategies for optimizing FMT formulations and systematically monitoring post-transplant microbiome dynamics. Through a comprehensive synthesis of evidence from clinical trials and preclinical studies, we elucidate the potential benefits and challenges of combining FMT with ICIs across diverse cancer types. While some studies report improved outcomes, others indicate no benefit or potential adverse effects, emphasizing the complexity of host-microbiome interactions in cancer immunotherapy. We outline critical research directions, encompassing the need for large-scale, multi-center randomized controlled trials, in-depth microbial ecology studies, and the integration of multi-omics approaches with artificial intelligence. Regulatory and ethical challenges are critically addressed, underscoring the imperative for standardized protocols and rigorous long-term safety assessments. This comprehensive review seeks to guide future research endeavors and clinical applications of FMT-ICIs combination therapy, with the potential to improve cancer patient outcomes while ensuring both safety and efficacy. As this rapidly evolving field advances, maintaining a judicious balance between openness to innovation and cautious scrutiny is crucial for realizing the full potential of microbiome modulation in cancer immunotherapy.

Clinical features and risk factors for combined Klebsiella pneumoniae infection in patients with liver cirrhosis

This article discusses the findings presented by Zhang et al. They analyzed the risk factors and clinical characteristics associated with Klebsiella pneumoniae infection in patients with liver cirrhosis treated at a hospital in Beijing. In this article, we focus on the connection between chronic kidney disease and the intestinal microbiota, and propose microbiota transplantation as a potential treatment for this patient group. We also examine an intriguing phenomenon related to hepatic encephalopathy, and provide insights into the future research.

Guidance for Fecal Microbiota Transplantation Trials in Ulcerative Colitis: The Second ROME Consensus Conference

BACKGROUND

Fecal microbiota transplantation (FMT) is emerging as a potential treatment modality for individuals living with inflammatory bowel disease (IBD). Despite its promise, the effectiveness of FMT for treating IBD, particularly for ulcerative colitis (UC), still requires thorough clinical investigation. Notwithstanding differences in methodologies, current studies demonstrate its potential for inducing remission in UC patients. Therefore, standardized and robust randomized clinical trials (RCTs) are needed to further support its efficacy for managing UC. The aim of the second Rome Consensus Conference was to address gaps and uncertainties identified in previous research regarding FMT and to offer a robust framework for future studies applied to the treatment of UC.

METHODS

Global experts in the field of clinical IBD, mucosal immunology, and microbiology (N = 48) gathered to address the need for standardized clinical trials in FMT investigation. The group focused on key issues, such as stool donation, donor selection, characterization of fecal biomass, potential administration routes, as well as the process of induction, maintenance, and endpoint readouts.

RESULTS AND CONCLUSIONS

The consensus achieved during this conference established standardization of methods and protocols to enhance the current quality of research, with the aim of eventual implementation of FMT in managing UC and the ultimate goal of improving patient outcomes.

Comparative effectiveness of treatments for recurrent Clostridioides difficile infection: a network meta-analysis of randomized controlled trials

Background

Clostridioides difficile infection (CDI) is the most common cause of healthcare-associated infectious diarrhea. A major clinical challenge is recurrent CDI (rCDI) without effective standard drug-based therapy. Additionally, a comprehensive comparison of various therapy effectiveness in rCDI patients is still under investigation.

Methods

A Bayesian network meta-analysis (NMA) of randomized control trials up to March 2024 was performed to investigate the efficacy of rCDI interventions.

Results

Seventeen trials were included, comprising 4,148 CDI patients with ten interventions, including fecal microbiota transplantation (FMT) by lower gastrointestinal (LGI), FMT by upper gastrointestinal (UGI), Autologous FMT (AFMT), vancomycin + FMT, vancomycin, placebo, fidaxomicin, Vowst (SER109), Rebyota (RBX2660), and monoclonal antibody. NMA showed that FMT by LGI had the highest efficacy in treating rCDIs with an odds ratio (95% confidence interval) of 32.33 (4.03, 248.69) compared with placebo. FMT by UGI also showed high efficacy, whereas the efficacy comparison between FMT by LGI and UGI was not statistically significant (ORs) (95% CI), 1.72 (0.65, 5.21). The rankogram and surface under the cumulative ranking curve (SUCRA) also showed FMT by LGI ranked at the top and FMT by UGI ranked second in the curative effect.

Conclusion

NMA demonstrates FMT's significant efficacy in rCDI management, regardless of administration route (lower or upper gastrointestinal). Despite its significant benefits, FMT's safety is a concern due to the lack of standardized FDAcompliant manufacturing and oversight. Microbiota-based therapies also exhibit potential. However, limited research mandates further clinical exploration. Antibiotics, in contrast, display comparatively reduced efficacy in rCDI, potentially linked to disruptions in native gut microflora balance.

Systematic Review

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=368435, Identifier CRD42022368435.

The Progression of Microbiome Therapeutics for the Management of Gastrointestinal Diseases and Beyond

There has been an increased ability to investigate the human microbiota through next-generation sequencing and functional assessment. This advancement has rapidly expanded our ability to study and manipulate the gastrointestinal microbiome to mitigate disease. Fecal microbiota transplantation, a therapy that broadly transfers the entire intestinal ecosystem, has been explored as a potential therapeutic in a variety of gastrointestinal, hepatic, and extraintestinal conditions. The field, however, continues to evolve, with a movement toward precision microbiome therapeutics, individualizing care for various disorders. This review will describe the use of fecal microbiota transplantation, microbiota restoration, and precision microbiome therapeutics, focusing on gastrointestinal and hepatic diseases.

BCAA mediated microbiota-liver-heart crosstalk regulates diabetic cardiomyopathy via FGF21

BACKGROUND

Diabetic cardiomyopathy (DCM) is one of leading causes of diabetes-associated mortality. The gut microbiota-derived branched-chain amino acids (BCAA) have been reported to play a central role in the onset and progression of DCM, but the potential mechanisms remain elusive.

RESULTS

We found the type 1 diabetes (T1D) mice had higher circulating BCAA levels due to a reduced BCAA degradation ability of the gut microbiota. Excess BCAA decreased hepatic FGF21 production by inhibiting PPARα signaling pathway and thereby resulted in a higher expression level of cardiac LAT1 via transcription factor Zbtb7c. High cardiac LAT1 increased the levels of BCAA in the heart and then caused mitochondrial damage and myocardial apoptosis through mTOR signaling pathway, leading to cardiac fibrosis and dysfunction in T1D mice. Additionally, transplant of faecal microbiota from healthy mice alleviated cardiac dysfunction in T1D mice, but this effect was abolished by FGF21 knockdown.

CONCLUSIONS

Our study sheds light on BCAA-mediated crosstalk among the gut microbiota, liver and heart to promote DCM and FGF21 serves as a key mediator. Video Abstract.

Fecal microbiota transplantation: current challenges and future landscapes

SUMMARYGiven the importance of gut microbial homeostasis in maintaining health, there has been considerable interest in developing innovative therapeutic strategies for restoring gut microbiota. One such approach, fecal microbiota transplantation (FMT), is the main "whole gut microbiome replacement" strategy and has been integrated into clinical practice guidelines for treating recurrent Clostridioides difficile infection (rCDI). Furthermore, the potential application of FMT in other indications such as inflammatory bowel disease (IBD), metabolic syndrome, and solid tumor malignancies is an area of intense interest and active research. However, the complex and variable nature of FMT makes it challenging to address its precise functionality and to assess clinical efficacy and safety in different disease contexts. In this review, we outline clinical applications, efficacy, durability, and safety of FMT and provide a comprehensive assessment of its procedural and administration aspects. The clinical applications of FMT in children and cancer immunotherapy are also described. We focus on data from human studies in IBD in contrast with rCDI to delineate the putative mechanisms of this treatment in IBD as a model, including colonization resistance and functional restoration through bacterial engraftment, modulating effects of virome/phageome, gut metabolome and host interactions, and immunoregulatory actions of FMT. Furthermore, we comprehensively review omics technologies, metagenomic approaches, and bioinformatics pipelines to characterize complex microbial communities and discuss their limitations. FMT regulatory challenges, ethical considerations, and pharmacomicrobiomics are also highlighted to shed light on future development of tailored microbiome-based therapeutics.

The use of faecal microbiota transplant as treatment for recurrent or refractory Clostridioides difficile infection and other potential indications: second edition of joint British Society of Gastroenterology (BSG) and Healthcare Infection Society (HIS) guidelines

The first British Society of Gastroenterology (BSG) and Healthcare Infection Society (HIS)-endorsed faecal microbiota transplant (FMT) guidelines were published in 2018. Over the past 5 years, there has been considerable growth in the evidence base (including publication of outcomes from large national FMT registries), necessitating an updated critical review of the literature and a second edition of the BSG/HIS FMT guidelines. These have been produced in accordance with National Institute for Health and Care Excellence-accredited methodology, thus have particular relevance for UK-based clinicians, but are intended to be of pertinence internationally. This second edition of the guidelines have been divided into recommendations, good practice points and recommendations against certain practices. With respect to FMT for Clostridioides difficile infection (CDI), key focus areas centred around timing of administration, increasing clinical experience of encapsulated FMT preparations and optimising donor screening. The latter topic is of particular relevance given the COVID-19 pandemic, and cases of patient morbidity and mortality resulting from FMT-related pathogen transmission. The guidelines also considered emergent literature on the use of FMT in non-CDI settings (including both gastrointestinal and non-gastrointestinal indications), reviewing relevant randomised controlled trials. Recommendations are provided regarding special areas (including compassionate FMT use), and considerations regarding the evolving landscape of FMT and microbiome therapeutics.

Expert consensus on the diagnosis and treatment of end-stage liver disease complicated by infections

End-stage liver disease (ESLD) is a life-threatening clinical syndrome and when complicated with infection the mortality is markedly increased. In patients with ESLD, bacterial or fungal infection can induce or aggravate the occurrence or progression of liver decompensation. Consequently, infections are among the most common complications of disease deterioration. There is an overwhelming need for standardized protocols for early diagnosis and appropriate management for patients with ESLD complicated by infections. Asia Pacific region has the largest number of ESLD patients, due to hepatitis B and the growing population of alcohol and NAFLD. Concomitant infections not only add to organ failure and high mortality but also to financial and healthcare burdens. This consensus document assembled up-to-date knowledge and experience from colleagues across the Asia-Pacific region, providing data on the principles as well as evidence-based current working protocols and practices for the diagnosis and treatment of patients with ESLD complicated by infections.

The use of faecal microbiota transplant as treatment for recurrent or refractory Clostridioides difficile infection and other potential indications: second edition of joint British Society of Gastroenterology (BSG) and Healthcare Infection Society (HIS) guidelines

The first British Society of Gastroenterology (BSG) and Healthcare Infection Society (HIS)-endorsed faecal microbiota transplant (FMT) guidelines were published in 2018. Over the past 5 years, there has been considerable growth in the evidence base (including publication of outcomes from large national FMT registries), necessitating an updated critical review of the literature and a second edition of the BSG/HIS FMT guidelines. These have been produced in accordance with National Institute for Health and Care Excellence-accredited methodology, thus have particular relevance for UK-based clinicians, but are intended to be of pertinence internationally. This second edition of the guidelines have been divided into recommendations, good practice points and recommendations against certain practices. With respect to FMT for Clostridioides difficile infection (CDI), key focus areas centred around timing of administration, increasing clinical experience of encapsulated FMT preparations and optimising donor screening. The latter topic is of particular relevance given the COVID-19 pandemic, and cases of patient morbidity and mortality resulting from FMT-related pathogen transmission. The guidelines also considered emergent literature on the use of FMT in non-CDI settings (including both gastrointestinal and non-gastrointestinal indications), reviewing relevant randomised controlled trials. Recommendations are provided regarding special areas (including compassionate FMT use), and considerations regarding the evolving landscape of FMT and microbiome therapeutics.

Research reviews and prospects of gut microbiota in liver cirrhosis: a bibliometric analysis (2001-2023)

INTRODUCTION

The gut-liver axis has emerged as a focal point in chronic liver disorders, prompting more research into the role of the gut microbiota in liver cirrhosis. In individuals with liver cirrhosis, changes in the structure and function of the gut microbiota are closely tied to clinical prognosis. However, there is a scarcity of bibliometric evaluations conducted in this particular field.

METHODS

This study is aiming to conduct a complete analysis of the knowledge structure and centers pertaining to gut microbiota in liver cirrhosis using bibliometric methods. Publications on gut microbiota and liver cirrhosis from 2001 to 2023 are sourced from the Web of Science Core Collection. For the bibliometric analysis, we employ VOSviewer, CiteSpace, and the R package "bibliometrix".

RESULTS

Our study encompasses a comprehensive collection of 3109 articles originating from 96 countries, with notable contributions from leading nations such as the United States and China. The quantity of publications concerning the gut microbiota of liver cirrhosis rises annually. The University of California San Diego, Virginia Commonwealth University, Zhejiang University are the primary research institutions. World Journal of Gastroenterology publishes the most papers in this field, while hepatology is the most frequently co-cited journal. These publications come from a total of 15,965 authors, and the most prolific authors are Bajaj Jasmohan S., Schnabl Bernd and Gillevet Patrick M., while the most co-cited authors are Bajaj Jasmohan S., Younossi Zobair M., and Reiner Wiest. In addition, "dysbiosis", "gut microbiota", "intestinal barrier", "fecal microbiota transplantation", and "complement-system" are the primary keywords of research trends in recent years.

DISCUSSION

This study offering a comprehensive insight into the research dynamics surrounding gut microbiota in patients with liver cirrhosis. It delineates the current research frontiers and hotspots, serving as a valuable guide for scholars.

Updated Insights into Probiotics and Hepatobiliary Diseases

Hepatobiliary diseases have a high prevalence worldwide, with a wide range of diseases involved in the liver and biliary system. Modifications in gut microbiota have been proven to have an association with unbalanced intestinal homeostasis and the dysfunction of host metabolism and the immune system, which can be the risk factors for many hepatobiliary diseases, such as nonalcoholic fatty liver disease (NAFLD), alcoholic liver disease (ALD), nonalcoholic fatty steatohepatitis (NASH), hepatitis, cirrhosis, hepatocellular carcinoma (HCC) and cholestasis, as well as infection due to liver transplantation. Probiotics are commonly used gut microbiota-targeted strategies to treat dysbiosis and intestinal dysfunction, as well as the gut-liver axis, which can enhance the effectiveness of probiotics in the management of liver diseases. Recent studies have explored more potential single or mixed strains of probiotics, and bioinformatics methods can be used to investigate the potential mechanisms of probiotics on liver diseases. In this review, we summarize the preclinical and clinical studies on the role of probiotics in hepatobiliary diseases from 2018 to 2023, revealing the possible mechanism of probiotics in the treatment of hepatobiliary diseases and discussing the limitations of probiotics in treating hepatobiliary diseases. This review provides updated evidence for the development of probiotic products, exploration of new probiotic strains, and support for clinical studies. Further studies should focus on the safety, viability, and stability of probiotics, as well as medication dosage and duration in clinical practice.

Faecal (or intestinal) microbiota transplant: a tool for repairing the gut microbiome

Faecal/intestinal microbiota transplant (FMT/IMT) is an efficacious treatment option for recurrent Clostridioides difficile infection, which has prompted substantial interest in FMT's potential role in the management of a much broader range of diseases associated with the gut microbiome. Despite its promise, the success rates of FMT in these other settings have been variable. This review critically evaluates the current evidence on the impact of clinical, biological, and procedural factors upon the therapeutic efficacy of FMT, and identifies areas that remain nebulous. Due to some of these factors, the optimal therapeutic approach remains unclear; for example, the preferred timing of FMT administration in a heavily antibiotic-exposed hematopoietic cell transplant recipient is not standardized, with arguments that can be made in alternate directions. We explore how these factors may impact upon more informed selection of donors, potential matching of donors to recipients, and aspects of clinical care of FMT recipients. This includes consideration of how gut microbiome composition and functionality may strategically inform donor selection criteria. Furthermore, we review how the most productive advances within the FMT space are those where clinical and translational outcomes are assessed together, and where this model has been used productively in recent years to better understand the contribution of the gut microbiome to human disease, and start the process toward development of more targeted microbiome therapeutics.

Engraftment of aging-related human gut microbiota and the effect of a seven-species consortium in a pre-clinical model

Human aging is characterized by gut microbiome alteration and differential loss of gut commensal species associated with the onset of frailty. The administration of cultured commensal strains to replenish lost taxa could potentially promote healthy aging. To investigate the interaction of whole microbiomes and administered strains, we transplanted gut microbiota from a frail or healthy elderly subject into germ-free mice. We supplemented the frail-donor recipient group with a defined consortium of taxa (the "S7") that we identified by analyzing healthy aging subjects in our previous studies and whose abundance correlated with health-promoting dietary intervention. Inoculation with a frail or a healthy donor microbiome resulted in differential microbiota compositions in murine recipients 5 weeks post-transplantation. Fecal acetate levels were significantly higher in healthy donor recipient mice than in frail donor recipient mice after 4 weeks. However, the frailty-related phenotype was not replicated in recipient mice with single-dose microbiota transplantation from a healthy and a frail donor. Five S7 species colonized successfully in germ-free mice, with a relatively high abundance of Barnesiella intestinihominis and Eubacterium rectale. The engraftment of five S7 species in germ-free mice increased fecal acetate levels and reduced colon permeability and plasma TNF-ɑ concentration. Supplementation with the S7 in frail-microbiota recipient mice did not increase alpha-diversity but significantly increased the abundance of Barnesiella intestinihominis. S7 supplementation showed the potential for improving spatial reference memory in frail-microbiota recipient mice. Collectively, these data highlight the challenge of elderly microbiota engraftment in the germ-free mouse model but show promise for modulating the gut microbiome of frail elderly subjects by administering an artificial gut microbe consortium associated with healthy aging.

Fecal Microbiota Transplantation in Liver Cirrhosis

The human gastrointestinal tract houses a diverse array of probiotic and pathogenic bacteria and any alterations in this microbial composition can exert a significant influence on an individual's well-being. It is well-established that imbalances in the gut microbiota play a pivotal role in the development of liver diseases. In light of this, a new adjuvant therapy for liver diseases could be regulating the intestinal microbiota. Through fecal microbiota transplantation, patients whose microbiomes are compromised are treated with stool from healthy donors in an attempt to restore a normal microbiome and alleviate their symptoms. A review of cross-sectional studies and case reports suggests that fecal microbiota transplants may offer effective treatment for chronic liver diseases. Adding to the potential of this emerging therapy, recent research has indicated that fecal microbiota transplantation holds promise as a therapeutic approach specifically for liver cirrhosis. By introducing a diverse range of beneficial microorganisms into the gut, this innovative treatment aims to address the microbial imbalances often observed in cirrhotic patients. While further validation is still required, these preliminary findings highlight the potential impact of fecal microbiota transplantation as a novel and targeted method for managing liver cirrhosis. We aimed to summarize the current state of understanding regarding this procedure, as a new therapeutic method for liver cirrhosis, as well as to explain its clinical application and future potential.

A meta-analysis of microbiome therapies for hepatic encephalopathy

Microbiome therapies may be reported to be effective in hepatic encephalopathy (HE). We thus did a meta-analysis of randomized controlled trials to assess the effect of microbiome therapies for HE. We systematically searched PubMed, Web of Science, EMBASE, and Cochrane Library for randomized controlled trials that compared the different treatments for HE including probiotics, symbiotics, and fecal microbiota transplant (FMT). Meta-analysis was performed to calculate pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs). Twenty-one studies met our inclusion criteria (N = 1746 participants). Probiotics, synbiotics and FMT significantly reversed minimal HE (MHE) (OR: 0.41, 95% CI: 0.19-0.90, P = 0.03), reduced overt HE (OHE) development (OR, 0.41; 95% CI: 0.28-0.61 P < 0.00001)and the frequency of serious adverse events(SAEs) (OR:0.14, 95% CI: 0.04-0.47, P = 0.001), meanwhile decreased ammonia levels (WMD: -9.26, 95% CI: -16.92 to -1.61; P = 0.02), NCT level (MD = -4.41, 95% CI: -0.87 to -0.22, P = 0.04) and hospitalization rates (OR, 0.38; 95% CI: 0.19-0.79, P = 0.009) compared with placebo/no treatment. Finally, we conclude that microbiome therapies were more effective in improving MHE and preventing progression to OHE, reducing the frequency of SAEs, and decreasing ammonia levels, NCT level, and hospitalization rates when compared to placebo/no treatment.

The pathogenesis of gut microbiota in hepatic encephalopathy by the gut-liver-brain axis

Hepatic encephalopathy (HE) is a neurological disease occurring in patients with hepatic insufficiency and/or portal-systemic blood shunting based on cirrhosis. The pathogenesis is not completely clear till now, but it is believed that hyperammonemia is the core of HE. Hyperammonemia caused by increased sources of ammonia and decreased metabolism further causes mental problems through the gut-liver-brain axis. The vagal pathway also plays a bidirectional role in the axis. Intestinal microorganisms play an important role in the pathogenesis of HE through the gut-liver-brain axis. With the progression of cirrhosis to HE, intestinal microbial composition changes gradually. It shows the decrease of potential beneficial taxa and the overgrowth of potential pathogenic taxa. Changes in gut microbiota may lead to a variety of effects, such as reduced production of short-chain fatty acids (SCFAs), reduced production of bile acids, increased intestinal barrier permeability, and bacterial translocation. The treatment aim of HE is to decrease intestinal ammonia production and intestinal absorption of ammonia. Prebiotics, probiotics, antibiotics, and fecal microbiota transplantation (FMT) can be used to manipulate the gut microbiome to improve hyperammonemia and endotoxemia. Especially the application of FMT, it has become a new treated approach to target microbial composition and function. Therefore, restoring intestinal microbial homeostasis can improve the cognitive impairment of HE, which is a potential treatment method.

Clostridioides difficile infection in patients with nonalcoholic fatty liver disease-current status

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, leading to fibrosis, cirrhosis and hepatocellular carcinoma and also associated with increased cardiovascular disease mortality. The pathogenesis of NAFLD is not fully understood, although NAFLD is thought to be a hepatic form of metabolic syndrome. There is an increasing understanding of the role of microbiota disturbances in NAFLD pathogenesis, and as with many other conditions affecting the microbiota, NAFLD may be a novel risk factor for Clostridioides difficile (C. difficile) colonization (CDC) and C. difficile infection (CDI). CDI is an emerging nosocomial disease, and community-acquired cases of infection are growing, probably due to an increase in CDC rates. The association of NAFLD with CDI has been shown in only 4 studies to date, three of which included less than 1000 patients, although the frequency of NAFLD in these studies was observed in almost 20% of the total patient cohort. These data revealed that NAFLD is a risk factor for CDI development and, moreover, is a risk factor for intestinal complications of CDI. More studies are needed to investigate this association and move forward CDC and CDI screening efforts for this group of patients.

Is it possible to intervene early cirrhosis by targeting toll-like receptors to rebalance the intestinal microbiome?

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.

Bibliometric and visual analysis of fecal microbiota transplantation research from 2012 to 2021

BACKGROUND

Fecal microbiota transplantation (FMT) is an emerging therapy for diseases associated with intestinal flora imbalance that has attracted increasing attention in recent years. This study aims to provide an overview of research trends in the field, and act as a reference point for future scientific research by analyzing the state of current research, identifying hotspots, and potential frontiers of FMT.

METHODS

Articles relating to FMT that were published between the years 2012 and 2021 were retrieved from the Web of Science Core Collection. Bibliometric analysis was performed using Microsoft Excel and CiteSpace.

RESULTS

A total of 2,403 English language articles relating to FMT research were published over the last ten years. Most of this research was carried out in the United States of America, with Harvard Medical school being the most productive institution. Much of the research was published in the PLoS One journal. Alexander Khoruts was identified as a prominent, productive researcher in the field. Keyword analysis revealed that research hot spots included gut microbiota, Clostridium difficile infection (CDI), and diseases. Burst detection indicated that future research frontiers include clinical practice guidelines and strategies.

CONCLUSION

Our analysis explored hot spots and emerging trends in the FMT field. Indications for use of FMT extended from digestive system diseases to other systemic diseases. Additionally, areas such as risk assessment and control, along with application methods were also a focus of current research. Moreover, research relating to optimization of clinical practice has excellent prospects.

Orchestrating the fecal microbiota transplantation: Current technological advancements and potential biomedical application

Fecal microbiota transplantation (FMT) has been proved to be an effective treatment for gastrointestinal disorders caused due to microbial disbalance. Nowadays, this approach is being used to treat extragastrointestinal conditions like metabolic and neurological disorders, which are considered to have their provenance in microbial dysbiosis in the intestine. Even though case studies and clinical trials have demonstrated the potential of FMT in treating a variety of ailments, safety and ethical concerns must be answered before the technique is widely used to the community's overall benefit. From this perspective, it is not unexpected that techniques for altering gut microbiota may represent a form of medication whose potential has not yet been thoroughly addressed. This review intends to gather data on recent developments in FMT and its safety, constraints, and ethical considerations.

Fecal microbiota transplant improves cognition in hepatic encephalopathy and its effect varies by donor and recipient

Early data suggest fecal microbiota transplant (FMT) may treat hepatic encephalopathy (HE). Optimal FMT donor and recipient characteristics are unknown. We assessed the safety and efficacy of FMT in patients with prior overt HE, comparing five FMT donors. We performed an open-label study of FMT capsules, administered 5 times over 3 weeks. Primary outcomes were change in psychometric HE score (PHES) and serious adverse events (SAEs). Serial stool samples underwent shallow shotgun metagenomic sequencing. Ten patients completed FMT administration and 6-month follow-up. Model for End-Stage Liver Disease (MELD) score did not change after FMT (14 versus 14, p = 0.51). Thirteen minor adverse events and three serious adverse events (two unrelated to FMT) were reported. One SAE was extended-spectrum beta-lactamase Escherichia coli bacteremia. The PHES improved after three doses of FMT (+2.1, p < 0.05), after five doses of FMT (+2.9, p = 0.007), and 4 weeks after the fifth dose of FMT (+3.1, p = 0.02). Mean change in the PHES ranged from -1 to +6 by donor. Two taxa were identified by random forest analysis and confirmed by linear regression to predict the PHES- Bifidobacterium adolescentis (adjusted R² = 0.27) and B. angulatum (adjusted R² = 0.25)-both short-chain fatty acid (SCFA) producers. Patients who responded to FMT had higher levels of Bifidobacterium as well as other known beneficial taxa at baseline and throughout the study. The FMT donor with poorest cognitive outcomes in recipients had the lowest fecal SCFA levels. Conclusion: FMT capsules improved cognition in HE, with an effect varying by donor and recipient factors (NCT03420482).

Fecal Microbiota Transplantation in Decompensated Cirrhosis: A Systematic Review on Safety and Efficacy

Background and Aims: Due to increasing knowledge of the “gut–liver axis”, there has been growing interest regarding the use of fecal microbiota transplant in the management of chronic liver disease. There are limited data available and current guidelines are mostly based on expert opinions. We aim to perform the first systematic review investigating safety and efficacy of fecal microbiota transplant particularly among high-risk decompensated cirrhosis patient populations. Methods: Literature search was performed using variations of the keywords “fecal microbiota transplant” and “cirrhosis” on PubMed/Medline from inception to 3 October 2021. The resulting 116 articles were independently screened by two authors. In total, 5 qualifying studies, including 2 randomized control trials and 3 retrospective case series, were found to meet established eligibility criteria and have adequate quality of evidence to be included in this review. Results: Of the total 58 qualifying patients, there were 2 deaths post fecal microbiota transplant, 1 of which could not rule out being related (1.7%). Among the remaining 56 participants, 8 serious adverse events were reported, of which 2 could not rule out being related (3.6%). The success rate of fecal microbiota transplantation in treating recurrent Clostridioides difficile infection among patients with decompensated cirrhosis was 77.8%. The success rate when used as investigational treatment for hepatic encephalopathy was 86.7%, with multiple studies reporting clinically significant improvement in encephalopathy testing scores. Conclusions: We found a marginally higher rate of deaths and serious adverse events from fecal microbiota transplant in our patient population compared with the average immunocompetent population, where it was previously found to have 0 deaths and SAE rate of 2.83%. The efficacy when used for recurrent C.difficile infection was 77.8% and 87% in the decompensated cirrhotic and general populations, respectively. Studies on efficacy in novel treatment of hepatic encephalopathy have been promising. This study concludes that fecal microbiota transplant use in decompensated cirrhosis patients should be used with caution and preferably be limited to research purposes until better data are available.

Clostridioides difficile Infection in Liver Cirrhosis: A Concise Review

Clostridium difficile is a Gram-positive bacillus with fecal-oral transmission and is currently one of the most common nosocomial infections worldwide, which was renamed Clostridioides difficile in 2016. Clostridioides difficile infection (CDI) is a prevalent infection in cirrhosis and negatively affects prognosis. This study aimed to provide a concise review with clinical practice implications. The prevalence of CDI in cirrhotic patients increases, while the associated mortality decreases. Multiple groups of risk factors increase the likelihood of CDI in patients with cirrhosis, such as antibiotic use, the severity of cirrhosis, some comorbidities, and demographic aspects. Treatment in the general population is currently described in the latest guidelines. In patients with cirrhosis, rifaximin and lactulose have been shown to reduce CDI risk due to their modulatory effects on the intestinal flora, although conflicting results exist. Fecal microbiota transplantation (FMT) as a treatment for the second or subsequent CDI recurrences has demonstrated a good safety and efficacy in cirrhosis and CDI. Future validation in more prospective studies is needed. Screening of asymptomatic patients appears to be discouraged for the prevention currently, with strict hand hygiene and cleaning of the ward and medical equipment surfaces being the cornerstone of minimizing transmission.

A Systematic Review of the Efficacy and Safety of Fecal Microbiota Transplantation in the Treatment of Hepatic Encephalopathy and Clostridioides difficile Infection in Patients With Cirrhosis

The microbiome of the human gut and liver coexists by influencing the health and disease state of each system. Fecal microbiota transplantation (FMT) has recently emerged as a potential treatment for conditions associated with cirrhosis, such as hepatic encephalopathy and recurrent/refractory Clostridioides difficile infection (rCDI). We have conducted a systematic review of the safety and efficacy of FMT in treating hepatic encephalopathy and rCDI. A literature search was performed using variations of the keywords "fecal microbiota transplant" and "cirrhosis" on PubMed/MEDLINE from inception to October 3, 2021. The resulting 116 articles were independently reviewed by two authors. Eight qualifying studies were included in the systematic review. A total of 127 cirrhotic patients received FMT. Hepatic encephalopathy was evaluated by cognitive tests, such as the Psychometric Hepatic Encephalopathy Score (PHES) and EncephalApp Stroop test. Not only was there an improvement in the cognitive performance in the FMT cohort, but the improvement was also maintained throughout long-term follow-up. In the treatment of rCDI, the FMT success rate is similar between cirrhotic patients and the general population, although more than one dose may be needed in the former. The rate of serious adverse events and adverse events in the cirrhotic cohort was slightly higher than that in the general population but was low overall. We found evidence that supports the therapeutic potential and safety profile of FMT to treat hepatic encephalopathy and rCDI in cirrhotic patients. Further research will be beneficial to better understand the role of FMT in cirrhosis.

An update on fecal microbiota transplantation for the treatment of gastrointestinal diseases

Our understanding of the microbiome and its implications for human health and disease continues to develop. Fecal microbiota transplantation (FMT) is now an established treatment for recurrent Clostridioides difficile infection. There is also increasing evidence for the efficacy of FMT in inducing remission for mild-moderate ulcerative colitis. However, for other indications, data for FMT are limited, with randomized controlled trials rare, typically small and often conflicting. Studies are continuing to explore the role of FMT for many other conditions, including Crohn's disease, functional gut disorders, metabolic syndrome, modulating responses to chemotherapy, eradication of multidrug resistant organisms, and the gut-brain axis. In light of safety, logistical, and regulatory challenges, there is a move to standardized products including narrow spectrum consortia. However, the mechanisms underpinning FMT remain incompletely understood, including the role of non-bacterial components, which may limit success of novel microbial approaches.

Clinical Practice Guidelines for Fecal Microbiota Transplantation in Korea

Fecal microbiota transplantation (FMT) is a highly efficacious and safe modality for the treatment of recurrent or refractory Clostridioides difficile infection (CDI), with overall success rates of 90%. Thus, FMT has been widely used for 10 years. The incidence and clinical characteristics of CDI, the main indication for FMT, differ between countries. To date, several guidelines have been published. However, most of them were published in Western countries and therefore cannot represent the Korean national healthcare systems. One of the barriers to performing FMT is a lack of national guidelines. Accordingly, multidisciplinary experts in this field have developed practical guidelines for FMT. The purpose of these guidelines is to aid physicians performing FMT, which can be adapted to treat CDI and other conditions.

Clinical Application and Progress of Fecal Microbiota Transplantation in Liver Diseases: A Review

The human gut harbors a dense and highly diverse microbiota of approximately 1,000 bacterial species. The interaction between the host and gut bacteria strongly influences human health. Numerous evidence suggest that intestinal flora imbalance is closely associated with the development and treatment of liver diseases, including acute liver injury and chronic liver diseases (cirrhosis, autoimmune liver disease, and fatty liver). Therefore, regulating the gut microbiota is expected to be a new method for the adjuvant treatment of liver diseases. Fecal microbiota transplantation (FMT) is defined as the transplantation of gut microbiota from healthy donors to sick patients via the upper or lower gastrointestinal route to restore the normal intestinal balance. In this study, we briefly review the current research on the gut microbiota and its link to liver diseases and then summarize the evidence to elucidate the clinical application and development of FMT in liver disease treatment.

Clostridioides difficile infection in liver cirrhosis patients: A population-based study in United States

BACKGROUND

Clostridioides (formerly Clostridium) difficile infection (CDI) is an increasingly frequent cause of morbidity and mortality in hospitalized patients. Multiple risk factors are documented in the literature that includes, but are not limited to, antibiotics use, advanced age, and gastric acid suppression. Several epidemiological studies have reported an increased incidence of CDI in advanced liver disease patients. Some have also demonstrated a higher prevalence of nosocomial infections in cirrhotic patients.

AIM

To use a large nationwide database, we sought to determine CDI’s risk among liver cirrhosis patients in the United States.

METHODS

We queried a commercial database (Explorys Inc^TM, Cleveland, OH, United States), and obtained an aggregate of electronic health record data from 26 major integrated United States healthcare systems comprising 360 hospitals in the United States from 2018 to 2021. Diagnoses were organized into the Systematized Nomenclature of Medicine Clinical Terms (SNOMED–CT) hierarchy. Statistical analysis for the multivariable model was performed using Statistical Package for Social Sciences (SPSS version 25, IBM Corp^TM). For all analyses, a two-sided P value of < 0.05 was considered statistically significant.

RESULTS

There were a total of 19387760 patients in the database who were above 20 years of age between the years 2018-2021. Of those, 133400 were diagnosed with liver cirrhosis. The prevalence of CDI amongst the liver cirrhosis population was 134.93 per 100.000 vs 19.06 per 100.000 in non-cirrhotic patients (P < 0.0001). The multivariate analysis model uncovered that cirrhotic patients were more likely to develop CDI (OR: 1.857; 95%CI: 1.665-2.113, P < 0.0001) compared to those without any prior history of liver cirrhosis.

CONCLUSION

In this large database study, we uncovered that cirrhotic patients have a significantly higher CDI prevalence than those without cirrhosis. Liver cirrhosis may be an independent risk factor for CDI. Further prospective studies are needed to clarify this possible risk association that may lead to the implementation of screening methods in this high-risk population.

The microbiota in cirrhosis and its role in hepatic decompensation

Cirrhosis - the common end-stage of chronic liver disease - is associated with a cascade of events, of which intestinal bacterial overgrowth and dysbiosis are central. Bacterial toxins entering the portal or systemic circulation can directly cause hepatocyte death, while dysbiosis also affects gut barrier function and increases bacterial translocation, leading to infections, systemic inflammation and vasodilation, which contribute to acute decompensation and organ failure. Acute decompensation and its severe forms, pre-acute-on-chronic liver failure (ACLF) and ACLF, are characterised by sudden organ dysfunction (and failure) and high short-term mortality. Patients with pre-ACLF and ACLF present with high-grade systemic inflammation, usually precipitated by proven bacterial infection and/or severe alcoholic hepatitis. However, no precipitant is identified in 30% of these patients, in whom bacterial translocation from the gut microbiota is assumed to be responsible for systemic inflammation and decompensation. Different microbiota profiles may influence the rate of decompensation and thereby outcome in these patients. Thus, targeting the microbiota is a promising strategy for the prevention and treatment of acute decompensation, pre-ACLF and ACLF. Approaches include the use of antibiotics such as rifaximin, faecal microbial transplantation and enterosorbents (e.g. Yaq-001), which bind microbial factors without exerting a direct effect on bacterial growth kinetics. This review focuses on the role of microbiota in decompensation and strategies targeting microbiota to prevent acute decompensation.

ACG Clinical Guidelines: Prevention, Diagnosis, and Treatment of Clostridioides difficile Infections

Clostridioides difficile infection occurs when the bacterium produces toxin that causes diarrhea and inflammation of the colon. These guidelines indicate the preferred approach to the management of adults with C. difficile infection and represent the official practice recommendations of the American College of Gastroenterology. The scientific evidence for these guidelines was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation process. In instances where the evidence was not appropriate for Grading of Recommendations Assessment, Development, and Evaluation but there was consensus of significant clinical merit, key concept statements were developed using expert consensus. These guidelines are meant to be broadly applicable and should be viewed as the preferred, but not the only, approach to clinical scenarios.

Safety of fecal microbiota transplantation for Clostridioides difficile infection focusing on pathobionts and SARS-CoV-2

Clostridioides difficile infection (CDI) is a consequence of flagrant use of antibiotics, an aging population with increasing comorbidities, and increased hospitalizations. The treatment of choice for CDI is antibiotics (vancomycin or fidaxomicin), with a possibility of recurrent CDI despite lack of additional risk factors for CDI. For the last 10 years, fecal microbiota transplantation (FMT) has emerged as a promising therapy for recurrent CDI, with success rates of over 85% compared with less than 50% with antibiotics for multiple recurrent CDI. Along with the success of FMT, several adverse and serious adverse events with FMT have been reported. These range from self-limiting abdominal pain to death due to severe sepsis. This review focuses on the safety of FMT, emphasizing the reports of transmission of pathobionts like extended-spectrum beta lactamase Escherichia coli and Shiga toxin-producing E. coli. The severe acute respiratory syndrome coronavirus-2 is a potential pathogen that could be transmitted via FMT during the COVID-19 pandemic. The challenges faced by clinicians for donor screening, clinical trials, and other aspects of FMT during the pandemic are discussed.

Fecal Microbiota Transplant in Cirrhosis Reduces Gut Microbial Antibiotic Resistance Genes: Analysis of Two Trials

Antibiotic resistance leads to poor outcomes in cirrhosis. Fecal microbiota transplant (FMT) is associated with reduction in antibiotic resistance gene (ARG) burden in patients without cirrhosis; however, the impact in cirrhosis is unclear. We aimed to study the effect of capsule and enema FMT on ARG abundance in fecal samples, which were collected during two published FMT trials in patients with cirrhosis on rifaximin, lactulose, and proton pump inhibitors. ARGs were identified using metagenomics and mapped against the Comprehensive Antibiotic Resistance Database. Changes in ARG abundance were studied within/between groups. The capsule FMT trial involved a one-time FMT or placebo capsule administration with stool collection at baseline and week 4 postintervention. Antibiotics+enema FMT included preprocedure antibiotics followed by FMT enema versus standard-of-care (SOC). Stool was collected at baseline, postantibiotics, and day 7/15 postintervention. Both trials included 20 patients each. There was no safety/infection signal linked to FMT. In the capsule trial, beta-lactamase (OXY/LEN) expression decreased post-FMT versus baseline. Compared to placebo, patients who were post-FMT had lower abundance of vancomycin (VanH), beta-lactamase (ACT), and rifamycin ARGs; the latter was associated with cognitive improvement. No changes were seen within patients treated with placebo. In the antibiotics+enema trial for postantibiotics at day 7 versus baseline, there was an increase in vancomycin and beta-lactamase ARGs, which decreased at day 15. However, quinolone resistance increased at day 15 versus baseline. Between SOC and FMT, day 7 had largely lower ARG (CfxA beta-lactamase, VanW, and VanX) that continued at day 15 (cepA beta-lactamase, VanW). No changes were seen within the SOC group. Conclusion: Despite differences in routes of administration and preintervention antibiotics, we found that ARG abundance is largely reduced after FMT compared to pre-FMT baseline and non-FMT groups in decompensated cirrhosis.