Gastric acid suppression promotes alcoholic liver disease by inducing overgrowth of intestinal Enterococcus

Engineered Probiotics Enable Targeted Gut Delivery of Dual Gasotransmitters for Inflammatory Bowel Disease Therapy

Inflammatory bowel disease (IBD) remains an incurable condition, often accompanied by high rates of anxiety and depression, further diminishing the quality of life of patients. Endogenous gasotransmitters, such as carbon monoxide (CO) and hydrogen sulfide (H₂S), exhibit potent anti-inflammatory and immunomodulatory effects. However, their therapeutic application is limited by challenges in targeted delivery to affected tissues. Here, we propose a novel strategy for targeted gut delivery of CO/H2S through engineering Escherichia coli Nissle 1917 (EcN) with CO/H2S-releasing copolymer (POSR) loading. This engineered probiotic (POSR@EcN) enhances EcN colonization in the intestine and enables controlled, localized release of CO/H2S at inflamed sites. The release of CO/H2S modulates inflammation, restores intestinal barrier integrity, and reshapes gut microbiota by promoting beneficial bacteria and increasing short-chain fatty acids production, effectively alleviating IBD symptoms. Notably, targeted CO/H2S delivery also elevates neuroprotective metabolites like indoleacetic acid and γ-aminobutyric acid, reducing neuroinflammation via the gut-brain axis and mitigating anxiety- and depression-like behaviors in IBD mice. This approach highlights the potential of EcN as a probiotic carrier for the targeted delivery of gasotransmitters, offering a promising strategy for IBD treatment.

Intestinal Microbes, Metabolites, and Hormones in Alcohol-Associated Liver Disease

Alcohol-associated liver disease (ALD)-encompassing conditions including steatosis, fibrosis, cirrhosis, and hepatocellular carcinoma-refers to hepatic damage arising from excessive or hazardous alcohol consumption, and is now recognized as a significant global health burden. Although the mechanisms underlying ALD remain incompletely understood, several pathways have been substantiated over the last five decades, notably the involvement of intestinal microorganisms and the involvement of the gut-liver axis in alcohol metabolism and ALD pathogenesis. Ethanol intake disrupts the intestinal microbial balance and compromises the gut barrier, resulting in increased permeability to microbial products. The subsequent translocation of microbial metabolites and other antigenic substances to the liver activates hepatic immune responses, thereby contributing to liver injury. In addition, gastrointestinal hormones are also implicated in ALD progression through various mechanisms. Although no therapies for ALD have been approved by the Food and Drug Administration, various therapeutic strategies targeting the intestinal microbiota and gut barrier have been identified. In conclusion, this review discusses the role of the gut-liver axis in alcohol metabolism and ALD pathogenesis and explores the emerging therapeutic strategies.

Multi-omics analyses of the gut microbiota and metabolites in children with metabolic dysfunction-associated steatotic liver disease

The development and severity of metabolic dysfunction-associated steatotic liver disease (MASLD) in children are closely related to alterations of gut microbiota. This study aims to investigate changes in the gut microbiota signature and microbial metabolites in children with MASLD. We collected fecal samples from children and adolescents aged 6-16 years, and the presence of MASLD was diagnosed by ultrasound. We performed 16S ribosomal DNA sequencing and targeted metabolomics in 36 and 25 subjects, consisting of healthy controls, children with obesity, and children with MASLD. The α-diversity was significantly lower in children with obesity and MASLD compared with healthy controls. Linear discriminant analysis of effect size analysis identified Anaerostipes and A. hadrus as the top biomarkers differentiating the obesity group from the MASLD group. In MASLD patients with high alanine aminotransferase values (≥50 U/L for boys and 44 U/L for girls), we observed a decrease in the gut microbiota health index. MASLD patients with high shear wave elastography (E) values (≥6.2 kPa) showed an increased abundance of Ruminococcus torques, which was positively correlated with the levels of deoxycholic acid (DCA) and E values. Importantly, the mediation analysis identified positive associations between R. torques and clinical indicators of MASLD that were mediated by DCA. Overall, our study suggests that gut microbiota and metabolites are significantly altered in children with MASLD, and targeting R. torques may offer potential benefits for disease management.IMPORTANCEThis study investigated alterations in the gut microbiota signature and microbial metabolites in children with metabolic dysfunction-associated steatotic liver disease (MASLD). We found that an increased abundance of Ruminococcus torques was associated with increased levels of deoxycholic acid and the progression of MASLD, suggesting that R. torques may serve as a novel clinical target in pediatric MASLD.

Sanye tablet regulates gut microbiota and bile acid metabolism to attenuate hepatic steatosis

ETHNOPHARMACOLOGICAL RELEVANCE

Sanye Tablet (SYT), a patent traditional Chinese prescription, is commonly used in treating type 2 diabetes mellitus and hyperlipidemia. Both clinical and animal studies suggest that SYT effectively regulates lipid metabolism. However, its mode of action on hepatic steatosis has yet to be fully elucidated.

AIM OF STUDY

This study investigates the lipid-regulating effects and underlying mechanism of SYT in high-fat diet (HFD)-induced hepatic steatosis mice.

MATERIAL AND METHODS

The inhibitory effects of SYT on developing hepatic steatosis were investigated in HFD-fed C57BL/6N mice. Biochemical markers, including total cholesterol (TC) and triglycerides (TG), were measured using specific kits. Hepatic histological alterations were determined by Hematoxylin and Eosin (H&E) and Oil Red O staining. Hepatic, fecal, and systemic bile acids (BAs) profiles were detected by UPLC-MS. mRNA and protein levels of BAs synthesis-related enzymes and critical nodes of farnesoid X receptor (FXR)/fibroblast growth factor 15 (FGF15)/fibroblast growth factor receptor 4 (FGFR4) signaling were detected. Fecal microbial composition was analyzed by 16S rRNA gene sequencing and the antimicrobial activity of SYT was further evaluated in vitro.

RESULTS

SYT alleviated HFD-induced hepatic steatosis by decreasing TG and TC levels, relieving hepatocyte ballooning, and promoting hepatic BAs synthesis. Moreover, SYT significantly increased the levels of taurine-conjugated BAs in the liver and feces, which in turn inhibited the FXR/FGF15/FGFR4 signaling. Consequently, the hepatic BAs synthesis-related enzyme expression was promoted to reduce lipid accumulation. Notably, SYT remodeled the gut microbiota composition of HFD-fed mice, especially inhibiting the growth of bile salt hydrolase (BSH)-producing bacteria, such as Lactobacillus murinus, Lactobacillus johnsonii, and Enterococcus faecalis.

CONCLUSION

The findings illustrated that SYT prevented hepatic steatosis by improving hepatic lipid accumulation, which is reflected in modulating the gut-liver axis. SYT corrects BAs profile, restores perturbed FXR/FGF15/FGFR4 signaling and promotes hepatic BAs synthesis, which is associated with modulation on certain BSH-producing bacteria.

Gut microbiota-mediated gut-liver axis: a breakthrough point for understanding and treating liver cancer

The trillions of commensal microorganisms living in the gut lumen profoundly influence the physiology and pathophysiology of the liver through a unique gut-liver axis. Disruptions in the gut microbial communities, arising from environmental and genetic factors, can lead to altered microbial metabolism, impaired intestinal barrier and translocation of microbial components to the liver. These alterations collaboratively contribute to the pathogenesis of liver disease, and their continuous impact throughout the disease course plays a critical role in hepatocarcinogenesis. Persistent inflammatory responses, metabolic rearrangements and suppressed immunosurveillance induced by microbial products underlie the pro-carcinogenic mechanisms of gut microbiota. Meanwhile, intrahepatic microbiota derived from the gut also emerges as a novel player in the development and progression of liver cancer. In this review, we first discuss the causes of gut dysbiosis in liver disease, and then specify the pivotal role of gut microbiota in the malignant progression from chronic liver diseases to hepatobiliary cancers. We also delve into the cellular and molecular interactions between microbes and liver cancer microenvironment, aiming to decipher the underlying mechanism for the malignant transition processes. At last, we summarize the current progress in the clinical implications of gut microbiota for liver cancer, shedding light on microbiota-based strategies for liver cancer prevention, diagnosis and therapy.

Enterococci for human health: A friend or foe?

Enterococci are widely distributed in nature and exhibit good temperature and pH tolerance, making them suitable for industrial fermentation. It can produce bacteriocins, natural antibacterial substances utilized in food preservation. Some Enterococci are employed as probiotics to regulate human immunity and maintain healthy intestinal environments. However, recent scientific studies have highlighted the pathogenicity and multidrug resistance of Enterococci, classifying it as an important pathogen in clinical infections. Moreover, increasing evidence has linked Enterococcus sp., particularly Enterococcus faecalis and Enterococcus faecium, to clinical diseases, raising concerns about their safety and posing the question, how should we approach the conflicting nature of the pathogenic and beneficial effects of Enterococci? This review provides the recent advancements in Enterococci research and incorporates the perspectives of international authoritative organizations and institutions to comprehensively analyze the beneficial and harmful characteristics of Enterococci in the fields of science, clinical and industrial applications, aiming to address three important questions: whether Enterococci are beneficial or harmful to humans, their potential use in medical treatments, and the criteria to evaluate their safety. The goal is to explore the feasibility of the standardized use of Enterococci and provide guidance on the scientific selection and utilization of probiotics.

The Protective Effect of Limosilactobacillus fermentum FZU501 Against Alcohol-Induced Liver Injury in Mice via Gut Microbiota-Liver Axis

As a probiotic strain isolated from Hongqu rice wine (a traditional Chinese fermented food), Limosilactobacillus fermentum FZU501 (designated as Lf) demonstrates exceptional gastric acid and bile salt tolerance, showing potential application as a functional food. The aim of this study was to investigate the protective effect of dietary Lf intervention on alcohol-induced liver injury (ALI) in mice. The results demonstrated that oral administration of Lf effectively ameliorated alcohol-induced lipid metabolism disorders by reducing the serum levels of TC, TG and LDL-C and increasing the serum levels of HDL-C. In addition, oral administration of Lf effectively prevented alcohol-induced liver damage by increasing the hepatic activities of antioxidant enzymes (CAT, SOD, GSH-Px) and alcohol-metabolizing enzymes (ADH and ALDH). Interestingly, 16S amplicon sequencing showed that oral administration of Lf increased the number of Prevotella, Lachnospiraceae_NK4A136_group and Lactobacillus, but decreased the proportion of Faecalibaculum, Adlercreutzia and Alistipes in the intestines of mice that consumed excessive alcohol, which was highly associated with improved liver function. As revealed by liver untargeted metabolomics studies, oral Lf clearly changed liver metabolic profiles, with the signature biomarkers mainly involving purine metabolism, taurine metabolism, tryptophan, alanine, aspartic acid and glutamate metabolism, etc. Additionally, Lf intervention regulated liver gene transcription in over-drinking mice for cholesterol metabolism, bile acid metabolism, fatty acid β-oxidation, alcohol metabolism and oxidative stress. Taken together, the above research results provide solid scientific support for the biological activity of Lf in ameliorating alcohol-induced liver metabolism disorder and intestinal microbiota imbalance.

Association of Enterococcus faecalis and tyrosine decarboxylase gene levels with levodopa pharmacokinetics in Parkinson's disease

Multiple factors affect the absorption of orally administered levodopa, the gold standard for the treatment of Parkinson's disease (PD). Enterococcus faecalis (E. faecalis) expresses the enzyme tyrosine decarboxylase (tyrDC), which metabolizes levodopa into dopamine and thereby may influence its absorption in patients with PD. This study investigated the association between fecal E. faecalis and tyrDC gene levels and the pharmacokinetics of orally administered levodopa in 21 patients with PD. Our results revealed a significant association between elevated fecal levels of E. faecalis and tyrDC gene levels and reduced peak plasma levodopa concentrations. Additionally, among patients receiving levodopa-carbidopa intestinal gel treatment, strong positive correlations were observed between E. faecalis and tyrDC gene levels in fecal samples and those from the tip of the jejunal tube. Further prospective studies are required to explore the potential role of gut microbiota as a therapeutic target in patients with PD.

Intestinal Microbiomics and Liver Metabolomics Insights into the Ameliorative Effects of Selenium-Enriched Lactobacillus fermentum FZU3103 on Alcohol-Induced Liver Injury in Mice

In this study, we investigated the ameliorative effects of selenium-enriched Lactobacillus fermentum FZU3103 (Lf@Se) and its pathway on alcoholic liver injury (ALI) in mice. The results showed that Lf@Se was superior to Lf and inorganic selenium in alleviating ALI. Oral Lf@Se effectively prevented lipid metabolism disorders, improved liver function, promoted alcohol metabolism, and alleviated liver oxidative damage in mice. 16S amplicons sequencing indicated that Lf@Se intervention modulated intestinal flora homeostasis by increasing (decreasing) the abundance of beneficial bacteria (harmful bacteria), which is associated with the improvement of liver function. Besides, Lf@Se intervention altered the liver metabolic profile, and the characteristic biomarkers were mainly involved in tyrosine metabolism, retinol metabolism, galactose metabolism, and primary bile acid biosynthesis. Additionally, Lf@Se intervention regulated liver gene expression for lipid metabolism and oxidative stress. Western blot analysis revealed increased expression levels of intestinal tight junction proteins after Lf@Se intervention, thereby ameliorating alcohol-induced intestinal barrier damage.

Gut-X axis

Recent advances in understanding the modulatory functions of gut and gut microbiota on human diseases facilitated our focused attention on the contribution of the gut to the pathophysiological alterations of many extraintestinal organs, including the liver, heart, brain, lungs, kidneys, bone, skin, reproductive, and endocrine systems. In this review, we applied the "gut-X axis" concept to describe the linkages between the gut and other organs and discussed the latest findings related to the "gut-X axis," including the underlying modulatory mechanisms and potential clinical intervention strategies.

Characterization of liver, adipose, and fecal microbiome in obese patients with MASLD: links with disease severity and metabolic dysfunction parameters

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) encompasses a range of histological findings from the generally benign simple steatosis to steatohepatitis (MASH) which can progress to fibrosis and cirrhosis. Several factors, including the microbiome, may contribute to disease progression.

RESULTS

Here, we demonstrate links between the presence and abundance of specific bacteria in the adipose and liver tissues, inflammatory genes, immune cell responses, and disease severity. Overall, in MASLD patients, we observed a generalized obesity-induced translocation of gut bacteria to hepatic and adipose tissues. We identified microbial patterns unique to more severely diseased tissues. Specifically, Enterococcus, Granulicatella, and Morganellaceae abundance is positively correlated with immune cell counts and inflammatory gene expression levels, and both genera are significantly enriched in MASH patients. Brevibacterium is enriched in adipose tissues of patients with liver fibrosis.

CONCLUSION

Together, these results provide further insight into the microbial factors that may be driving disease severity. Video Abstract.

Selenium enrichment enhances the alleviating effect of Lactobacillus rhamnosus GG on alcoholic liver injury in mice

Selenium-enriched probiotics have attracted much attention due to the physiological activities of both probiotics and selenium (organic selenium). In this study, we investigated the mitigating effect of selenium-enriched Lactobacillus rhamnosus GG (LGG@Se) and its pathway on alcohol-induced liver injury (ALI) in mice. The results showed that LGG@Se was superior to LGG and sodium selenite in alleviating ALI. Oral LGG@Se effectively prevented lipid metabolism disorders and liver oxidative damage in mice caused by excessive alcohol intake. 16S amplicon sequencing showed that LGG@Se intervention increased the abundance of beneficial bacteria and suppressed the growth of harmful bacteria in the intestinal tract of over-drinking mice, and thus effectively modulated the homeostasis of intestinal flora, which were highly correlated with the improvement of liver function. Liver metabolomics analysis indicated that LGG@Se intervention altered liver metabolic profiling, and the characteristic biomarkers were mainly involved in amino acid metabolism, including alanine, aspartate and glutamate metabolism, arginine biosynthesis, etc. In addition, LGG@Se intervention modulated the expression of genes and proteins related to lipid metabolism and oxidative stress in liver of over-drinking mice. Western blot analysis revealed that LGG@Se intervention up-regulated the expression of intestinal barrier function-related proteins, thereby ameliorating alcohol-induced intestinal barrier damage. Collectively, these findings provide scientific evidence that LGG@Se possesses the biological activity of improving alcohol-induced lipid metabolism and intestinal microbiota disorder.

Metabolomics combined with network pharmacology reveals the protective effect of astragaloside IV on alcoholic liver disease

BACKGROUND

Alcoholic liver disease (ALD) is a significant contributor to liver damage. However, the clinical options for the treatment of ALD are limited. Astragaloside IV (AST-IV) is a saponin isolated from Astragalus membranaceus (AM). This study aimed to explore the underlying mechanisms of action of AST-IV in ALD by integrating metabolomics and network pharmacology.

METHODS

Sprague-Dawley (SD) rats were used to establish a rat model of ALD. AST-IV and polyene phosphatidyl choline (PPC; a positive control drug) were administered to rats with ALD for 4 weeks. We measured the body weight, liver index, ALT, AST, TC, TG, inflammatory markers (IL-1β, IL-6, and TNF-α), and oxidative stress markers (SOD, MDA) and used H&E and ORO staining to evaluate the hepatoprotective effect of both AST-IV and PPC on ALD. Subsequently, we performed untargeted metabolomics to predict the influence of AST-IV on lipid metabolism in rats with ALD. We then used a network pharmacology approach to identify the core targets through which AST-IV corrected lipid metabolism disorders and validated these targets through molecular docking, qRT-PCR and western blot analyses. Finally, we calculated the relationships between ALD-related biochemical markers, differential liver metabolites, and core targets using Spearman's correlation analysis.

RESULTS

AST-IV improved pathological damage and reduced lipid accumulation in the hepatocytes of rats with ALD. Furthermore, AST-IV inhibited oxidative stress and inflammatory responses in rats with ALD. The metabolomic results showed that AST-IV corrected hepatic lipid metabolism disorders by targeting linoleic acid, necrosis, sphingolipid, and glycerophospholipid metabolism. The Network pharmacology analysis revealed that the core targets of AST-IV exerting the above effects were p-RIPK3, p-MLKL, CYP1A2, CYP2C19, PPARα, PCSK9. Spearman's correlation analysis showed a strong correlation between ALD-related serum biochemical indices, core targets, and liver differential metabolites.

CONCLUSION

AST-IV corrects the metabolic disorders of linoleic acid, sphingolipid, and glycerophospholipid, and alleviates necrosis in rats with ALD through the core targets p-RIPK3, p-MLKL, CYP1A2, CYP2C19, PPARα, and PCSK9. This study is the first to reveal the mechanism of ALD protection through AST-IV from the perspective of metabolomics and network pharmacology. Therefore, a novel target has been identified to exert protection against ALD. This study provides a reference for ALD treatment.

Gut-liver axis: Recent concepts in pathophysiology in alcohol-associated liver disease

The growing recognition of the role of the gut microbiome's impact on alcohol-associated diseases, especially in alcohol-associated liver disease, emphasizes the need to understand molecular mechanisms involved in governing organ-organ communication to identify novel avenues to combat alcohol-associated diseases. The gut-liver axis refers to the bidirectional communication and interaction between the gut and the liver. Intestinal microbiota plays a pivotal role in maintaining homeostasis within the gut-liver axis, and this axis plays a significant role in alcohol-associated liver disease. The intricate communication between intestine and liver involves communication between multiple cellular components in each organ that enable them to carry out their physiological functions. In this review, we focus on novel approaches to understanding how chronic alcohol exposure impacts the microbiome and individual cells within the liver and intestine, as well as the impact of ethanol on the molecular machinery required for intraorgan and interorgan communication.

Comparative genomic and metabolomic analysis reveals the potential of a newly isolated Enterococcus faecium B6 involved in lipogenic effects

Evidence has indicated that Enterococcus plays a vital role in non-alcoholic fatty liver disease (NAFLD) development. However, the microbial genetic basis and metabolic potential in the disease are yet unknown. We previously isolated a bacteria Enterococcus faecium B6 (E. faecium B6) from children with NAFLD for the first time. Here, we aim to systematically investigate the potential of strain B6 in lipogenic effects. The lipogenic effects of strain B6 were explored in vitro and in vivo. The genomic and functional characterizations were investigated by whole-genome sequencing and comparative genomic analysis. Moreover, the metabolite profiles were unraveled by an untargeted metabolomic analysis. We demonstrated that strain B6 could effectively induce lipogenic effects in the liver of mice. Strain B6 contained a circular chromosome and two circular plasmids and posed various functions. Compared to the other two probiotic strains of E. faecium, strain B6 exhibited unique functions in pathways of ABC transporters, phosphotransferase system, and amino sugar and nucleotide sugar metabolism. Moreover, strain B6 produced several metabolites, mainly enriched in the protein digestion and absorption pathway. The unique potential of strain B6 in lipogenic effects was probably associated with glycolysis, fatty acid synthesis, and glutamine and choline transport. This study pioneeringly revealed the metabolic characteristics and specific detrimental traits of strain B6. The findings provided new insights into the underlying mechanisms of E. faecium in lipogenic effects, and laid essential foundations for further understanding of E. faecium-related disease.

Ellagic Acid Protects against Alcohol-Related Liver Disease by Modulating the Hepatic Circadian Rhythm Signaling through the Gut Microbiota-NPAS2 Axis

Alcohol-related liver disease (ALD) encompasses a spectrum of hepatic disorders resulting from alcohol abuse, which constitutes the predominant etiology of morbidity and mortality associated with hepatic pathologies globally. Excessive alcohol consumption disrupts the integrity of the intestinal barrier and perturbs the balance of gut microbiota, thereby facilitating the progression of ALD. Ellagic acid (EA) has been extensively reported to be an effective intervention for alleviating liver symptoms. However, the target molecules of EA in improving ALD and its underlying mechanism remain elusive. First, our study indicates that EA ameliorated ALD through the hepatic circadian rhythm signaling by up-regulating neuronal PAS domain protein 2 (NPAS2). Furthermore, analysis of the intestinal microbiome showed that EA significantly enhanced the abundance of beneficial bacteria, which was positively correlated with NPAS2 expression and negatively correlated with liver injury. Finally, antibiotic treatment and fecal microbiota transplantation (FMT) experiments established a causal relationship between the reshaped microbiota and NPAS2 in the amelioration of ALD. In summary, our study demonstrates novel evidence that EA attenuated ALD by modulating the hepatic circadian rhythm signaling pathway via the gut microbiota-NPAS2 axis, providing valuable insights for EA and microbiome-targeted interventions against ALD.

Gut Bacteria in Alcohol-Associated Liver Disease

Alcohol-associated liver disease (ALD) poses a significant global public health challenge, with high patient mortality rates and economic burden. The gut microbiome plays an important role in the onset and progression of alcohol-associated liver disease. Excessive alcohol consumption disrupts the intestinal barrier, facilitating the entry of harmful microbes and their products into the liver, exacerbating liver damage. Dysbiosis, marked by imbalance in gut bacteria, correlates with ALD severity. Promising microbiota-centered therapies include probiotics, phages, and fecal microbiota transplantation. Clinical trials demonstrate the potential of these interventions to improve liver function and patient outcomes, offering a new frontier in ALD treatment.

Schisandra chinensis polysaccharide prevents alcohol-associated liver disease in mice by modulating the gut microbiota-tryptophan metabolism-AHR pathway axis

Polysaccharides are one of the main active components of Schisandra chinensis and have been shown to possess diverse biological activities. In this study, we investigated the preventive effect of Schisandra chinensis polysaccharide (SCP) on alcohol-associated liver disease (ALD) by chronic-plus-binge ethanol feeding and the underlying mechanisms. The results suggest that supplementation with SCP prevents ALD by modulating gut microbiota and tryptophan (Trp) metabolism. SCP significantly enriched intestinal Lactobacillus, especially Lactobacillus reuteri, restored the content of intestinal indole derivatives (TRM, IAA, ILA, IALD) that can activate the aromatic hydrocarbon receptor (AHR), increased the colon AHR pathway activity, repaired intestinal barriers damage, reduced the circulating LPS, and inhibited the liver inflammation, oxidative stress, and lipid accumulation. The in vitro Trp metabolizing capacity was used to selected for a strain of L.reuteri whose in vitro proliferation was similarly promoted by SCP. Importantly, the gavage of the L.reuteri increased intestinal TRM content in mice. In addition, its ALD preventive effects were consistent with SCP and dependent on the colon AHR pathway. Our findings confirm that SCP may prevent ALD by mudulating the gut microbial-Trp metabolism-AHR pathway axis, suggesting that supplementation with the prebiotic SCP is an effective way to prevent ALD.

Effect of concomitant use of esomeprazole on levodopa pharmacokinetics and clinical symptoms in patients with Parkinson's disease

BACKGROUND

Proton pump inhibitors (PPIs), which inhibit gastric acid secretion, are frequently prescribed to patients with Parkinson's disease (PD). Levodopa, the gold-standard treatment for PD, demonstrates enhanced solubility in acidic environments. Although PPIs increase gastric pH and may affect levodopa absorption, the effect of concomitant PPI use on levodopa pharmacokinetics in patients with PD remains unknown. This study aimed to investigate the effect of the concomitant use of esomeprazole, a PPI, on the pharmacokinetics of levodopa and carbidopa and clinical symptoms in patients with PD.

METHODS

We prospectively enrolled 40 patients with PD and compared the pharmacokinetics of levodopa and carbidopa and clinical symptoms before and two weeks after the concomitant use of esomeprazole.

RESULTS

The plasma concentrations of levodopa 30 min after concomitant oral administration of levodopa and esomeprazole were significantly lower (4.92 ± 4.10 μmol/L) than those without concomitant esomeprazole use (6.26 ± 3.75 μmol/L; p = 0.027). The plasma concentrations of carbidopa showed no significant differences with respect to concomitant esomeprazole use. Significant elevation was recorded in all subscores of the Movement Disorder Society-sponsored revision of the Unified Parkinson's disease Rating Scale scores after concomitant use of esomeprazole. No significant differences were observed between Helicobacter pylori-negative and Helicobacter pylori-positive patients. Non-elderly patients (age ≤ 70 years) tended to be more susceptible to the effect of esomeprazole on levodopa pharmacokinetics and clinical symptoms.

CONCLUSIONS

The unnecessary use of PPIs should be avoided in patients with PD, especially in non-elderly patients, to improve absorption of levodopa.

Proton Pump Inhibitors and Oral-Gut Microbiota: From Mechanism to Clinical Significance

Proton pump inhibitors (PPIs) are some of the most commonly prescribed drugs worldwide, but there are increasing concerns about digestive complications linked to PPIs. Next-generation sequencing studies have suggested that PPIs can significantly affect the composition of the gut microbiota, which in turn may substantially contribute to the development of these complications. Recently, emerging evidence has suggested that the translocation of oral microbes into the gut may be the primary mechanism underlying the alterations in the gut microbiota induced by PPIs in the presence of gastric acid suppression and impaired oral-gut barrier function. Moreover, the significance of oral-gut microbial translocation in health and disease conditions has gained increasing recognition. Consequently, it is imperative to enhance our understanding of the functions of the oral-gut microbiota axis in digestive disorders associated with PPI therapies. This review aims to summarize current research findings and further elucidate the contribution of the oral-gut microbiota to the pathogenesis of PPI-related digestive diseases. We aim to provide a theoretical foundation for future therapeutic and preventive strategies targeting PPI-related digestive complications through modulation of the oral-gut microbiota.

Enterococcus faecalis: an overlooked cell invader

SUMMARYEnterococcus faecalis and Enterococcus faecium are human pathobionts that exhibit a dual lifestyle as commensal and pathogenic bacteria. The pathogenic lifestyle is associated with specific conditions involving host susceptibility and intestinal overgrowth or the use of a medical device. Although the virulence of E. faecium appears to benefit from its antimicrobial resistance, E. faecalis is recognized for its higher pathogenic potential. E. faecalis has long been considered a predominantly extracellular pathogen; it adheres to and is taken up by a wide range of mammalian cells, albeit with less efficiency than classical intracellular enteropathogens. Carbohydrate structures, rather than proteinaceous moieties, are likely to be primarily involved in the adhesion of E. faecalis to epithelial cells. Consistently, few adhesins have been implicated in the adhesion of E. faecalis to epithelial cells. On the host side, very little is known about cognate receptors, except for the role of glycosaminoglycans during macrophage infection. Several lines of evidence indicate that E. faecalis internalization may involve a zipper-like mechanism as well as a macropinocytosis pathway. Conversely, E. faecalis can use several strategies to prevent engulfment in phagocytes. However, the bacterial and host mechanisms underlying cell infection by E. faecalis are still in their infancy. The most recent striking finding is the existence of an intracellular lifestyle where E. faecalis can replicate within a variety of host cells. In this review, we summarize and discuss the current knowledge of E. faecalis-host cell interactions and argue on the need for further mechanistic studies to prevent or reduce infections.

Enterococcal-host interactions in the gastrointestinal tract and beyond

The gastrointestinal tract (GIT) is typically considered the natural niche of enterococci. However, these bacteria also inhabit extraintestinal tissues, where they can disrupt organ physiology and cause life-threatening infections. Here, we discuss how enterococci, primarily Enterococcus faecalis, interact with the intestine and other host anatomical locations such as the oral cavity, heart, liver, kidney, and vaginal tract. The metabolic flexibility of these bacteria allows them to quickly adapt to new environments, promoting their persistence in diverse tissues. In transitioning from commensals to pathogens, enterococci must overcome harsh conditions such as nutrient competition, exposure to antimicrobials, and immune pressure. Therefore, enterococci have evolved multiple mechanisms to adhere, colonize, persist, and endure these challenges in the host. This review provides a comprehensive overview of how enterococci interact with diverse host cells and tissues across multiple organ systems, highlighting the key molecular pathways that mediate enterococcal adaptation, persistence, and pathogenic behavior.

Fecal gelatinase does not predict mortality in patients with alcohol-associated hepatitis

Alcohol-associated liver disease is highly prevalent worldwide, with alcohol-associated hepatitis as a severe form characterized by substantial morbidity, mortality, and economic burden. Gut bacterial dysbiosis has been linked to progression of alcohol-associated hepatitis. Fecal cytolysin secreted by the pathobiont Enterococcus faecalis (E. faecalis) is associated with increased mortality in patients with alcohol-associated hepatitis. Although gelatinase is considered a virulence factor in E. faecalis, its prevalence and impact on alcohol-associated hepatitis patient outcomes remains unclear. In this study, 20 out of 65 (30.8%) patients with alcohol-associated hepatitis tested positive for gelatinase in their stool. There were no significant differences in 30-day and 90-day mortality between gelatinase-positive and gelatinase-negative patients (p=0.97 and p=0.48, respectively). Fecal gelatinase had a low discriminative ability for 30-day mortality (area under the curve [AUC] 0.50 vs fibrosis-4 Index (FIB-4) 0.75) and 90-day mortality compared with other established liver disease markers (AUC 0.57 vs FIB-4 0.79 or 'age, serum bilirubin, INR, and serum creatinine' (ABIC) score 0.78). Furthermore, fecal gelatinase was not an important feature for 30-day or 90-day mortality per random forest analysis. Finally, gelatinase-positive patients with alcohol-associated hepatitis did not exhibit more severe liver disease compared with gelatinase-negative patients. In conclusion, fecal gelatinase does not predict mortality or disease severity in patients with alcohol-associated hepatitis from our cohort.

Proton pump inhibitor use is associated with increased liver steatosis

Despite proton pump inhibitors (PPIs) being generally safe, there are questions about their potential long-term complications. The present study aimed to investigate the association between PPI therapy and the incidence of hepatic steatosis and liver fibrosis in the outpatient population of the United States. The present study included 7,395 individuals aged ≥20 years who underwent hepatic vibration-controlled transient elastography (VCTE) examination. The data were obtained from the January 2017 to March 2020 pre-pandemic National Health and Nutrition Examination Survey. Among the 7,395 adults who were included (mean age, 50.59 years; 3,656 male), 9.8% were prescribed PPIs. Following multivariable adjustment, the use of PPIs was significantly associated with hepatic steatosis [odds ratio (OR), 1.25; 95% confidence interval (CI), 1.02-1.53]. Prolonged use of PPIs was found to increase the risk of developing hepatic steatosis over time (P=0.006). Sensitivity analyses using different definitions of hepatic steatosis, such as a controlled attenuation parameter ≥285 dB/m (OR, 1.19; CI, 1.01-1.40), non-alcoholic fatty liver disease (OR, 1.50; 95% CI, 1.16-1.93) and metabolic dysfunction-associated steatotic liver disease (OR, 1.26; 95% CI, 1.05-1.52), consistently demonstrated an association between PPI prescription and hepatic steatosis. The administration of PPI therapy was linked with hepatic steatosis in US adults, although no significant association was observed with liver stiffness, as determined by VCTE.

Infectious Complications of Portal Hypertension

Patients with cirrhosis and clinically significant portal hypertension are at high risk of developing bacterial infections (BIs) that are the most common trigger of acute decompensation and acute-on-chronic liver failure. Furthermore, after decompensation, the risk of developing BIs further increases in an ominous vicious circle. BIs may be subtle, and they should be ruled out in all patients at admission and in case of deterioration. Timely administration of adequate empirical antibiotics is the cornerstone of treatment. Herein, we reviewed current evidences about pathogenesis, clinical implications and management of BIs in patients with cirrhosis and portal hypertension.

Endogenous ethanol production in health and disease

The gut microbiome exerts metabolic actions on distal tissues and organs outside the intestine, partly through microbial metabolites that diffuse into the circulation. The disruption of gut homeostasis results in changes to microbial metabolites, and more than half of the variance in the plasma metabolome can be explained by the gut microbiome. Ethanol is a major microbial metabolite that is produced in the intestine of nearly all individuals; however, elevated ethanol production is associated with pathological conditions such as metabolic dysfunction-associated steatotic liver disease and auto-brewery syndrome, in which the liver's capacity to metabolize ethanol is surpassed. In this Review, we describe the mechanisms underlying excessive ethanol production in the gut and the role of ethanol catabolism in mediating pathogenic effects of ethanol on the liver and host metabolism. We conclude by discussing approaches to target excessive ethanol production by gut bacteria.

Direct effects of alcohol on gut-epithelial barrier: Unraveling the disruption of physical and chemical barrier of the gut-epithelial barrier that compromises the host-microbiota interface upon alcohol exposure

The development of alcohol-associated diseases is multifactorial, mechanism of which involves metabolic alteration, dysregulated immune response, and a perturbed intestinal host-environment interface. Emerging evidence has pinpointed the critical role of the intestinal host-microbiota interaction in alcohol-induced injuries, suggesting its contribution to disease initiation and development. To maintain homeostasis in the gut, the intestinal mucosa serves as the first-line defense against exogenous factors in the gastrointestinal tract, including dietary contents and the commensal microbiota. The gut-epithelial barrier comprises a physical barrier lined with a single layer of intestinal epithelial cells and a chemical barrier with mucus trapping host regulatory factors and gut commensal bacteria. In this article, we review recent studies pertaining to the disrupted gut-epithelial barrier upon alcohol exposure and examine how alcohol and its metabolism can affect the regulatory ability of intestinal epithelium.

Individualized prevention of proton pump inhibitor related adverse events by risk stratification

Proton pump inhibitors (PPIs) are commonly used for gastric acid-related disorders, but their safety profile and risk stratification for high-burden diseases need further investigation. Analyzing over 2 million participants from five prospective cohorts from the US, the UK, and China, we found that PPI use correlated with increased risk of 15 leading global diseases, such as ischemic heart disease, diabetes, respiratory infections, and chronic kidney disease. These associations showed dose-response relationships and consistency across different PPI types. PPI-related absolute risks increased with baseline risks, with approximately 82% of cases occurring in those at the upper 40% of the baseline predicted risk, and only 11.5% of cases occurring in individuals at the lower 50% of the baseline risk. While statistical association does not necessarily imply causation, its potential safety concerns suggest that personalized use of PPIs through risk stratification might guide appropriate decision-making for patients, clinicians, and the public.

Gut Bacteria Provide Genetic and Molecular Reporter Systems to Identify Specific Diseases

With genetic information gained from next-generation sequencing (NGS) and genome-wide association studies (GWAS), it is now possible to select for genes that encode reporter molecules that may be used to detect abnormalities such as alcohol-related liver disease (ARLD), cancer, cognitive impairment, multiple sclerosis (MS), diabesity, and ischemic stroke (IS). This, however, requires a thorough understanding of the gut-brain axis (GBA), the effect diets have on the selection of gut microbiota, conditions that influence the expression of microbial genes, and human physiology. Bacterial metabolites such as short-chain fatty acids (SCFAs) play a major role in gut homeostasis, maintain intestinal epithelial cells (IECs), and regulate the immune system, neurological, and endocrine functions. Changes in butyrate levels may serve as an early warning of colon cancer. Other cancer-reporting molecules are colibactin, a genotoxin produced by polyketide synthetase-positive Escherichia coli strains, and spermine oxidase (SMO). Increased butyrate levels are also associated with inflammation and impaired cognition. Dysbiosis may lead to increased production of oxidized low-density lipoproteins (OX-LDLs), known to restrict blood vessels and cause hypertension. Sudden changes in SCFA levels may also serve as a warning of IS. Early signs of ARLD may be detected by an increase in regenerating islet-derived 3 gamma (REG3G), which is associated with changes in the secretion of mucin-2 (Muc2). Pro-inflammatory molecules such as cytokines, interferons, and TNF may serve as early reporters of MS. Other examples of microbial enzymes and metabolites that may be used as reporters in the early detection of life-threatening diseases are reviewed.

Gut-Liver Axis Dysregulation in Portal Hypertension: Emerging Frontiers

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.

Alterations in gut microbiota and bile acids by proton-pump inhibitor use and possible mediating effects on elevated glucose levels and insulin resistance

Several observational studies have suggested that proton-pump inhibitor (PPI) use might increase diabetes risk, but the mechanism remains unclear. This study aimed to investigate the effects of PPI use on gut microbiota and bile acids (BAs) profiles, and to explore whether these changes could mediate the association of PPIs use with fasting blood glucose (FBG) levels and insulin resistance (IR) in Chinese population. A cross-sectional study was conducted in Shenzhen, China, from April to August 2021, enrolled 200 eligible patients from the local hospital. Participants completed a questionnaire and provided blood and stool samples. Gut microbiome was measured by16S rRNA gene sequencing, and bile acids were quantified by UPLC-MS/MS. Insulin resistance (IR) was assessed using the Homeostasis Model Assessment 2 (HOMA2-IR). PPI use was positively associated with higher levels of FBG and HOMA2-IR after controlling for possible confounders. PPI users exhibited a decreased Firmicutes and an increase in Bacteroidetes phylum, alongside higher levels of glycoursodeoxycholic acid (GUDCA) and taurochenodeoxycholic acid (TCDCA). Higher abundances of Bacteroidetes and Fusobacterium as well as higher levels of TCDCA in PPI users were positively associated with elevated FBG or HOMA2-IR. Mediation analyses indicated that the elevated levels of FBG and HOMA2-IR with PPI use were partially mediated by the alterations in gut microbiota and specific BAs (i.e., Fusobacterium genera and TCDCA). Long-term PPI use may increase FBG and HOMA2-IR levels, and alterations in gut microbiota and BAs profiles may partially explain this association.

Long-term Use of Proton Pump Inhibitors is Associated With An Increased Risk of Nonalcoholic Fatty Liver Disease

BACKGROUNDS

The adverse effects of long-term use of proton pump inhibitors (PPIs) have led to growing concern. The association between PPIs use and the risks of nonalcoholic fatty liver disease (NAFLD) remains controversial.

GOAL

The aim of this study was to investigate the association between PPIs use and the risks of NAFLD among the general adult population in the United States.

STUDY

We performed a cross-sectional study by extracting data from the National Health and Nutrition Examination Survey of 2017 to 2018. The association between PPIs use and NAFLD risks was analyzed by weighted multivariate logistic regression.

RESULTS

Among the 4238 participants included in this study, 2167 were diagnosed with NAFLD. In the multivariate logistic regression model, PPIs use was associated with increased risks of NAFLD [odds ratio (OR): 1.318, 95% CI: 1.044-1.663; P=0.020]. This association was nonsignificant in participants taking PPIs for ˂5 years (OR: 0.846, 95% CI: 0.579-1.238; P=0.390), whereas it remained significant in participants taking PPIs for more than 5 years (OR: 2.016, 95% CI: 1.366-2.975; P=0.031). Further analysis showed that the use of PPIs was positively associated with risks of severe hepatic steatosis (OR: 1.451, 95% CI: 1.034-2.036; P=0.031) but not with mild-to-moderate steatosis (OR: 1.242, 95% CI: 0.886-1.741; P=0.208).

CONCLUSIONS

This study indicated that taking PPIs was associated with increased risks of NAFLD, especially severe hepatic steatosis. Awareness should be raised regarding the potential risks of NAFLD when prescribing PPIs.

Bacillus coagulans regulates gut microbiota and ameliorates the alcoholic-associated liver disease in mice

Introduction

Alcoholic-associated liver diseases (ALD) are now widespread issues worldwide. Alcoholic-induced chronic dysbiosis of the gut microbiota is one of the factors in the pathophysiology of ALD.

Methods

In this work, we employed a chronic-binge ethanol feeding mice model, as described in a previous report.

Results

Our findings demonstrate that hepatic inflammatory injury damage and accumulation of fat can be effectively reduced in mice with ALD by altering the gut microbiota utilizing Bacillus coagulans. Treatment with B. coagulans significantly modulates the levels of TNF-α, IL-1β, and IL-22 cytokines while maintaining tight junction proteins and mucin protein expressions to support intestinal barrier function restoration. Treatment with B. coagulans also alters the composition of the gut microbiota and increases the production of short-chain fatty acids (SCFAs).

Discussion

This is mostly due to B. coagulans promotes the growth of bacteria that produce SCFAs, such as Ruminococcus species and Akkermansia, while inhibiting the growth of pathogenic bacteria like Escherichia Shigella. Moreover, treatment with B. coagulans causes levels of 2-Ketobutyric acid, ketoleucine, and indoleacetic acid increase while homovanillic acid and 3'-O-Methylguanosine metabolites decrease significantly. This study facilitates the development of therapeutic and preventive strategies for ALD using lactic acid bacteria.

Enterococci facilitate polymicrobial infections

Enterococci are ubiquitous members of the gut microbiota in human beings and animals and are among the most important nosocomial organisms. Due to their opportunistic pathogenicity, enterococci are referred to as pathobionts and play decisive roles in a diverse array of polymicrobial infections. Enterococci can promote the colonization, pathogenesis, and persistence of various pathogens, compromise the efficacy of drugs, and pose a severe threat to public health. Most current treatments tend to focus on the sole pathogenic bacteria, with insufficient attention to the driving role of enterococci. In this review, we summarize the characteristics of enterococci in infections, the factors facilitating their outgrowth, as well as the sites and types of enterococci-associated polymicrobial infections. We present an overview of the underlying mechanisms of enterococci-mediated pathogenesis in polymicrobial infections. Furthermore, we discuss alternative strategies and potential intervention approaches to restrict such infections, shedding light on the discovery and development of new therapies against polymicrobial infections.

Mefentrifluconazole exposure disrupted hepatic lipid metabolism disorder tightly associated with gut barrier function abnormal in mice

Mefentrifluconazole (MFZ) is an azole fungicide that is placed in agriculture for the control of fungal hazards. However, due to their non-biodegradability, azole fungicides can accumulate in plants, animals, and the environment, thus becoming a major health concern worldwide. In this study, we exposed 7-week-old C57BL/6 mice to 10, 30, and 100 mg/kg of MFZ for 28 d to assess the toxic effects of MFZ on the liver and gut tissues of the mice. Histopathological, biochemical indexes, and transcriptomic analyses revealed that MFZ exposure disrupted the liver structure and hepatic lipid metabolism as well as damaged gut barrier function and promoted inflammation in mice. Moreover, 16S rRNA sequencing demonstrated that MFZ exposure significantly increased the abundance of patescibacteria at the generic level. Also, MFZ exposure increased the abundance of bacterial genera associated with inhibition of glycolipid metabolism. These results suggested that the disruption of liver lipid metabolism caused by MFZ exposure may be caused by changes in gut microbiota function. This study provided a new disease occurrence study for risk assessment of MFZ and strengthened the focus on some novel fungicides.

Consensus document on acute-on-chronic liver failure (ACLF) established by the Mexican Association of Hepatology

Acute-on chronic liver failure (ACLF) has been an intensively debated topic mainly due to the lack of a unified definition and diagnostic criteria. The growing number of publications describing the mechanisms of ACLF development, the progression of the disease, outcomes and treatment has contributed to a better understanding of the disease, however, it has also sparked the debate about this condition. As an attempt to provide medical professionals with a more uniform definition that could be applied to our population, the first Mexican consensus was performed by a panel of experts in the area of hepatology in Mexico. We used the most relevant and impactful publications along with the clinical and research experience of the consensus participants. The consensus was led by 4 coordinators who provided the most relevant bibliography by doing an exhaustive search on the topic. The entire bibliography was made available to the members of the consensus for consultation at any time during the process and six working groups were formed to develop the following sections: 1.- Generalities, definitions, and criteria, 2.- Pathophysiology of cirrhosis, 3.- Genetics in ACLF, 4.- Clinical manifestations, 5.- Liver transplantation in ACLF, 6.- Other treatments.

Commensal bacteria promote azathioprine therapy failure in inflammatory bowel disease via decreasing 6-mercaptopurine bioavailability

Azathioprine (AZA) therapy failure, though not the primary cause, contributes to disease relapse and progression in inflammatory bowel disease (IBD). However, the role of gut microbiota in AZA therapy failure remains poorly understood. We found a high prevalence of Blautia wexlerae in patients with IBD with AZA therapy failure, associated with shorter disease flare survival time. Colonization of B. wexlerae increased inflammatory macrophages and compromised AZA's therapeutic efficacy in mice with intestinal colitis. B. wexlerae colonization reduced 6-mercaptopurine (6-MP) bioavailability by enhancing selenium-dependent xanthine dehydrogenase (sd-XDH) activity. The enzyme sd-XDH converts 6-MP into its inactive metabolite, 6-thioxanthine (6-TX), thereby impairing its ability to inhibit inflammation in mice. Supplementation with Bacillus (B.) subtilis enriched in hypoxanthine phosphoribosyltransferase (HPRT) effectively mitigated B. wexlerae-induced AZA treatment failure in mice with intestinal colitis. These findings emphasize the need for tailored management strategies based on B. wexlerae levels in patients with IBD.

Fungal plasma biomarkers in patients admitted for inpatient treatment of alcohol use disorder

BACKGROUND

Fungal plasma biomarkers have not been studied in patients with unhealthy alcohol use and no apparent end-stage liver disease.

METHODS

We examined the prevalence of fungal plasma biomarkers, assessed by the presence of anti-Saccharomyces cerevisiae antibodies (ASCA; IgA and IgM), and its disease correlates in patients with alcohol use disorder (AUD). We performed logistic regression analyses to detect the association between clinical and laboratory characteristics and the presence of fungal plasma biomarkers.

RESULTS

We included 395 patients (75.9% male, median age of 49 years, and median body mass index of 25.6) who drank a median of 150 g of alcohol daily and had a median duration of AUD of 20 years. ASCA IgA and IgG were present in 34.4% and 14.9%, respectively, and 9.9% had both ASCA IgA and ASCA IgG. The presence of ASCA IgA was associated with male sex (p < 0.01); values of serum aspartate transferase (AST) (p = 0.02), gamma-glutamyl transferase (GGT) (p < 0.01), alkaline phosphatase (ALP) (p < 0.01), and bilirubin in the highest quartile (p < 0.01); Fibrosis-4 Index (FIB-4) values suggestive of advanced liver fibrosis (p < 0.01); and values of the macrophage activation factors sCD163 (p < 0.01) and sCD14 (p < 0.01), the cytokine IL-6 (p = 0.01), and lipopolysaccharide-binding protein in the highest quartile (p < 0.01). The presence of ASCA IgG was associated with omeprazole use (p = 0.04); values of AST (p = 0.04) and GGT (p = 0.04) in the highest quartile; FIB-4 values suggestive of advanced liver fibrosis (p < 0.01); and values of sCD163 (p < 0.01) in the highest quartile. The variables associated with the presence of both ASCA IgA and IgG were male sex (p = 0.04) and values of GGT (p = 0.04) and sCD163 in the highest quartile (p < 0.01).

CONCLUSIONS

In AUD patients, the presence of fungal biomarkers in plasma was common and associated with FIB-4 values suggestive of advanced liver fibrosis and with markers of liver damage, monocyte activation, and microbial translocation, male gender, and omeprazole use. These findings suggest that the presence of plasma anti-Saccharomyces cerevisiae antibodies could be used as a biomarker for an elevated risk of progressive liver disease in patients with AUD.

Proton pump inhibitors may enhance the risk of digestive diseases by regulating intestinal microbiota

Proton pump inhibitors (PPIs) are the most used acid-inhibitory drugs, with a wide range of applications in the treatment of various digestive diseases. However, recently, there has been a growing number of digestive complications linked to PPIs, and several studies have indicated that the intestinal flora play an important role in these complications. Therefore, developing a greater understanding of the role of the gut microbiota in PPI-related digestive diseases is essential. Here, we summarize the current research on the correlation between PPI-related digestive disorders and intestinal flora and establish the altered strains and possible pathogenic mechanisms of the different diseases. We aimed to provide a theoretical basis and reference for the future treatment and prevention of PPI-related digestive complications based on the regulation of the intestinal microbiota.

IgY antibodies against cytolysin reduce ethanol-induced liver disease in mice

BACKGROUND AND AIMS

Patients with severe alcohol-associated hepatitis have high morbidity and mortality. Novel therapeutic approaches are urgently needed. The aims of our study were to confirm the predictive value of cytolysin-positive Enterococcus faecalis ( E. faecalis ) for mortality in patients with alcohol-associated hepatitis and to assess the protective effect of specific chicken immunoglobulin Y (IgY) antibodies against cytolysin in vitro and in a microbiota-humanized mouse model of ethanol-induced liver disease.

APPROACH AND RESULTS

We investigated a multicenter cohort of 26 subjects with alcohol-associated hepatitis and confirmed our previous findings that the presence of fecal cytolysin-positive E. faecalis predicted 180-day mortality in those patients. After combining this smaller cohort with our previously published multicenter cohort, the presence of fecal cytolysin has a better diagnostic area under the curve, better other accuracy measures, and a higher odds ratio to predict death in patients with alcohol-associated hepatitis than other commonly used liver disease models. In a precision medicine approach, we generated IgY antibodies against cytolysin from hyperimmunized chickens. Neutralizing IgY antibodies against cytolysin reduced cytolysin-induced cell death in primary mouse hepatocytes. The oral administration of IgY antibodies against cytolysin decreased ethanol-induced liver disease in gnotobiotic mice colonized with stool from cytolysin-positive patients with alcohol-associated hepatitis.

CONCLUSIONS

E. faecalis cytolysin is an important mortality predictor in alcohol-associated hepatitis patients, and its targeted neutralization through specific antibodies improves ethanol-induced liver disease in microbiota-humanized mice.

Proton pump inhibitor treatment is associated with acute-on-chronic liver failure in patients with advanced cirrhosis

BACKGROUND

Acute-on-chronic liver failure (ACLF) is a fatal complication of cirrhosis. Hence, identification of risk factors for ACLF is crucial. Previous studies have linked proton pump inhibitor (PPI) treatment to complications of cirrhosis, however, a possible effect of PPI treatment on the risk of ACLF has not been investigated yet. Therefore, the present study aimed to characterize the impact of PPI treatment on ACLF development.

METHODS

A total of 642 patients hospitalized due to complications of cirrhosis were retrospectively identified, and PPI treatment during an observation period of 3 years following the hospitalization was reviewed. Subsequently, 74 patients with newly initiated PPI treatment at the time of hospitalization (PPI group) were 1:1 propensity score matched to 74 patients who received no PPI treatment (no-PPI group). Primary end point was the development of ACLF during the observation period, and secondary endpoints were mortality and upper gastrointestinal bleeding.

RESULTS

PPI and no-PPI groups had comparably severe chronic liver disease at baseline. Nevertheless, the cumulative incidence of ACLF in the presence of death as competing risk was markedly higher in the PPI group compared with the no-PPI group. ACLF-related deaths contributed significantly to a higher 3-year mortality in the PPI group. Uni and multivariable competing risk regression models confirmed that PPI treatment was an independent predictor of ACLF in the study collective (subdistribution HR: 1.892, 95% CI: 1.092-3.281, p = 0.023). The impact of PPI treatment on ACLF development was particularly strong in patients with a model for end-stage liver disease score >12. Upper gastrointestinal bleeding was slightly less frequent in the PPI group.

CONCLUSIONS

The present results indicate that PPI treatment could be a risk factor for ACLF in patients with advanced cirrhosis.

Increased mortality in patients with hematologic malignancies treated with proton pump inhibitors: a nationwide cohort study

Proton Pump inhibitors (PPIs) are frequently prescribed to cancer patients to prevent gastric mucosal damage. Post-diagnostic PPI use in patients with solid tumors may be associated with increased cancer mortality. However, the hazardous impact of PPIs in patients with hematologic malignancies remains unknown. This association was investigated in a large, retrospective cohort study using data from the Danish nationwide health registries. The outcomes were cancer-specific or non-cancer deaths. We identified 15,320 patients with hematologic malignancies and of these 1811 were identified as post-diagnostic PPI users. PPI users had significantly increased HRs for cancer-specific mortality (HR 1.31; 95% CI, 1.18-1.44) and 1-year cancer-specific mortality (HR 1.50, 95% CI 1.29-1.74) as compared to nonusers. The association between PPI use and increased cancer-specific mortality in Danish patients with hematologic malignancies supports the raised concerns regarding the frequent use of PPIs in cancer patients.

Meta-analysis of the effects of proton pump inhibitors on the human gut microbiota

Mounting evidence has linked changes in human gut microbiota to proton pump inhibitor (PPI) use. Accordingly, multiple studies have analyzed the gut microbiomes of PPI users, but PPI-microbe interactions are still understudied. Here, we performed a meta-analysis of four studies with available 16S rRNA gene amplicon sequencing data to uncover the potential changes in human gut microbes among PPI users. Despite some differences, we found common features of the PPI-specific microbiota, including a decrease in the Shannon diversity index and the depletion of bacteria from the Ruminococcaceae and Lachnospiraceae families, which are crucial short-chain fatty acid-producers. Through training based on multiple studies, using a random forest classification model, we further verified the representativeness of the six screened gut microbial genera and 20 functional genes as PPI-related biomarkers, with AUC values of 0.748 and 0.879, respectively. Functional analysis of the PPI-associated 16S rRNA microbiome revealed enriched carbohydrate- and energy-associated genes, mostly encoding fructose-1,6-bisphosphatase and pyruvate dehydrogenase, among others. In this study, we have demonstrated alterations in bacterial abundance and functional metabolic potential related to PPI use, as a basis for future studies on PPI-induced adverse effects.

Impaired flux of bile acids from the liver to the gut reveals microbiome-immune interactions associated with liver damage

Currently, there is evidence that alteration in the gut ecosystem contributes to the development of liver diseases, however, the complex mechanisms involved are still unclear. We induced cholestasis in mice by bile duct ligation (BDL), mirroring the phenotype of a bile duct obstruction, to understand how gut microbiota alterations caused by an impaired flow of bile acid to the gut contribute to the pathogenesis and progression of liver disease. We performed longitudinal stool, heart, and liver sampling using mice receiving BDL and controls receiving sham operation (ShamOP). Shotgun metagenomics profiling using fecal samples taken before and on day 1, day 3, and day 7 after surgery was performed, and the cytokines and clinical chemistry profiles from heart blood, as well as the liver bile acids profile, were measured. The BDL surgery reshaped the microbiome of mice, resulting in highly distinct characteristics compared to the ShamOP. Our analysis of the microbiome pathways and ECs revealed that BDL reduces the production of hepatoprotective compounds in the gut, such as biotin, spermidine, arginine, and ornithine, which were negatively associated with inflammatory cytokines (IL-6, IL-23, MCP-1). The reduction of the functional potential of the gut microbiota in producing those hepatoprotective compounds is associated with the decrease of beneficial bacteria species from Anaerotruncus, Blautia, Eubacterium, and Lachnoclostridium genera, as well as the increase of disease-associated bacteria e.g., Escherichia coli and Entercoccus faecalis. Our findings advances our knowledge of the gut microbiome-bile acids-liver triangle, which may serve as a potential therapeutic strategy for liver diseases.

Long-Term Use of Proton Pump Inhibitors Disrupts Intestinal Tight Junction Barrier and Exaggerates Experimental Colitis

BACKGROUND

Proton pump inhibitors [PPIs] are widely used to treat a number of gastro-oesophageal disorders. PPI-induced elevation in intragastric pH may alter gastrointestinal physiology. The tight junctions [TJs] residing at the apical intercellular contacts act as a paracellular barrier. TJ barrier dysfunction is an important pathogenic factor in inflammatory bowel disease [IBD]. Recent studies suggest that PPIs may promote disease flares in IBD patients. The role of PPIs in intestinal permeability is not clear.

AIM

The aim of the present study was to study the effect of PPIs on the intestinal TJ barrier function.

METHODS

Human intestinal epithelial cell culture and organoid models and mouse IBD models of dextran sodium sulphate [DSS] and spontaneous enterocolitis in IL-10-/- mice were used to study the role of PPIs in intestinal permeability.

RESULTS

PPIs increased TJ barrier permeability via an increase in a principal TJ regulator, myosin light chain kinase [MLCK] activity and expression, in a p38 MAPK-dependent manner. The PPI-induced increase in extracellular pH caused MLCK activation via p38 MAPK. Long-term PPI administration in mice exaggerated the increase in intestinal TJ permeability and disease severity in two independent models of DSS colitis and IL-10-/- enterocolitis. The TJ barrier disruption by PPIs was prevented in MLCK-/- mice. Human database studies revealed increased hospitalizations associated with PPI use in IBD patients.

CONCLUSIONS

Our results suggest that long-term use of PPIs increases intestinal TJ permeability and exaggerates experimental colitis via an increase in MLCK expression and activity.

Macrophage-derived MLKL in alcohol-associated liver disease: Regulation of phagocytosis

BACKGROUND AND AIMS

Mixed lineage kinase domain-like pseudokinase (MLKL), a key terminal effector of necroptosis, also plays a role in intracellular vesicle trafficking that is critical for regulating liver inflammation and injury in alcohol-associated liver disease (ALD). Although receptor interacting protein kinase 3 (Rip3)-/- mice are completely protected from ethanol-induced liver injury, Mlkl-/- mice are only partially protected. Therefore, we hypothesized that cell-specific functions of MLKL may contribute to ethanol-induced injury.

APPROACH AND RESULTS

Bone marrow transplants between Mlkl-/- mice and littermates were conducted to distinguish the role of myeloid versus nonmyeloid Mlkl in the Gao-binge model of ALD. Ethanol-induced hepatic injury, steatosis, and inflammation were exacerbated in Mlkl-/- →wild-type (WT) mice, whereas Mlkl deficiency in nonmyeloid cells (WT→ Mlkl-/- ) had no effect on Gao-binge ethanol-induced injury. Importantly, Mlkl deficiency in myeloid cells exacerbated ethanol-mediated bacterial burden and accumulation of immune cells in livers. Mechanistically, challenging macrophages with lipopolysaccharide (LPS) induced signal transducer and activator of transcription 1-mediated expression and phosphorylation of MLKL, as well as translocation and oligomerization of MLKL to intracellular compartments, including phagosomes and lysosomes but not plasma membrane. Importantly, pharmacological or genetic inhibition of MLKL suppressed the phagocytic capability of primary mouse Kupffer cells (KCs) at baseline and in response to LPS with/without ethanol as well as peripheral monocytes isolated from both healthy controls and patients with alcohol-associated hepatitis. Further, in vivo studies revealed that KCs of Mlkl-/- mice phagocytosed fewer bioparticles than KCs of WT mice.

CONCLUSION

Together, these data indicate that myeloid MLKL restricts ethanol-induced liver inflammation and injury by regulating hepatic immune cell homeostasis and macrophage phagocytosis.

Recent Advances in Understanding of Pathogenesis of Alcohol-Associated Liver Disease

Alcohol-associated liver disease (ALD) is one of the major diseases arising from chronic alcohol consumption and is one of the most common causes of liver-related morbidity and mortality. ALD includes asymptomatic liver steatosis, fibrosis, cirrhosis, and alcohol-associated hepatitis and its complications. The progression of ALD involves complex cell-cell and organ-organ interactions. We focus on the impact of alcohol on dysregulation of homeostatic mechanisms and regulation of injury and repair in the liver. In particular, we discuss recent advances in understanding the disruption of balance between programmed cell death and prosurvival pathways, such as autophagy and membrane trafficking, in the pathogenesis of ALD. We also summarize current understanding of innate immune responses, liver sinusoidal endothelial cell dysfunction and hepatic stellate cell activation, and gut-liver and adipose-liver cross talk in response to ethanol. In addition,we describe the current potential therapeutic targets and clinical trials aimed at alleviating hepatocyte injury, reducing inflammatory responses, and targeting gut microbiota, for the treatment of ALD.

Lack of Faecalibacterium prausnitzii and Bifidobacterium is associated with a higher risk of metabolic associated fatty liver disease in young-onset type 2 diabetes

Background

The incidence of comorbidity between type 2 diabetes mellitus (T2DM) and metabolic-associated fatty liver disease (MAFLD) is high, and patients tend to be younger. When people develop metabolic diseases such as T2DM and MAFLD, the original homeostasis of the gut microbiota in the body is disrupted, and gut flora drift occurs. This study investigated the relationship between the number of gut flora and MAFLD in young-onset T2DM.

Methods

This retrospective study analyzed 44 adolescent T2DM patients who were divided into a non-MAFLD group and a MAFLD group. Anthropometric measurements, clinical and biochemical markers, inflammatory markers, thyroid function assessments, and stool specimens were collected. Real-time PCR was performed to quantify several important gut flora constituents at the genus level. Student’s t-test and the chi-square test were applied for group comparisons, and binary regression models were used to explore the relationship between gut flora and MAFLD in young-onset T2DM.

Results

Among the 44 subjects, 26 (59.1%) were diagnosed with MAFLD, and 18 (40.9%) were not. Compared with the non-MAFLD group, body mass index (BMI), abdominal circumference, and levels of blood uric acid and thyroid stimulating hormone (TSH) in the MAFLD group were significantly increased, and age level and high-density lipoprotein cholesterol (HDL-C) were significantly decreased (p < 0.05). Compared with the non-MAFLD group, the abundance of Faecalibacterium prausnitzii and Bifidobacterium in the MAFLD group was significantly reduced, and the abundance of Enterococcus and Lactobacillus was significantly increased (p < 0.05). In the multivariate regression analysis, Faecalibacterium prausnitzii and Bifidobacterium were independent protective factors for MAFLD in young-onset T2DM, after excluding confounding factors.

Conclusion

In young-onset T2DM, there was a difference in gut flora between patients with MAFLD and those without MAFLD. Faecalibacterium prausnitzii and Bifidobacterium were independent protective factors for MAFLD in young-onset T2DM.

Endogenous n-3 PUFAs Improve Non-Alcoholic Fatty Liver Disease through FFAR4-Mediated Gut-Liver Crosstalk

The gut-liver axis plays a key role in the development and progression of non-alcoholic fatty liver disease (NAFLD). Due to the complexity and incomplete understanding of the cross-talk between the gut and liver, effective therapeutic targets are largely unknown. Free fatty acid receptors (FFARs) may bridge the cross-talk between the gut and liver. FFAR4 has received considerable attention due to its important role in lipid metabolism. However, the role of FFAR4 in this cross talk in NAFLD remains unclear. In this study, mice with high endogenous n-3 PUFAs but FFAR4 deficiency were generated by crossbreeding Fat-1 and FFAR4 knockout mice. FFAR4 deficiency blocked the protective effects of high endogenous n-3 PUFAs on intestinal barrier dysfunction and hepatic steatosis. In addition, FFAR4 deficiency decreased gut microbiota diversity and enriched Rikenella, Anaerotruncus, and Enterococcus, and reduced Dubosiella, Ruminococcaceae UCG-010, Ruminococcaceae UCG-014, Coriobacteriaceae UCG-002, Faecalibaculum, Ruminococcaceae UCG-009, and Akkermansia. Notably, FFAR4 deficiency co-regulated pantothenic acid and CoA biosynthesis, β-alanine metabolism, and sphingolipid metabolism pathways in the gut and liver, potentially associated with the aggravation of NAFLD. Together, the beneficial effects of n-3 PUFAs on the gut and liver were mediated by FFAR4, providing insights on the role of FFAR4 in the treatment of NAFLD through the gut-liver axis.