Akkermansia muciniphila in the small intestine improves liver fibrosis in a murine liver cirrhosis model.

Recent evidence indicates that liver cirrhosis (LC) is a reversible condition, but there is no established intervention against liver fibrosis. Although the gut microbiota is considered involved in the pathogenesis of LC, the underlying mechanisms remain unclear. Although the antibiotic, rifaximin (RFX), is effective for hepatic encephalopathy (HE) with LC, the impact of RFX on intestinal bacteria is unknown. We investigated the bacterial compositions along the GI tract under RFX treatment using a murine LC model. RFX improved liver fibrosis and hyperammonemia and altered the bacterial composition in the small intestine. The efficacy of RFX was associated with increases in specific bacterial genera, including Akkermansia. Administration of a commensal strain of Akkermansia muciniphila improved liver fibrosis and hyperammonemia with changing bacterial composition in the small intestine. This study proposed a new concept "small intestine-liver axis" in the pathophysiology of LC and oral A. muciniphila administration is a promising microbial intervention.

Altered blood microbiome in patients with HCV-related Child-Pugh class B cirrhosis.

BACKGROUND: Altered bacterial translocation is associated with changes in hepatic function and the progression from compensated to decompensated cirrhosis. Child-Turcotte-Pugh (CTP) score is an essential indicator of liver severity. Thus, we aimed to study differences in the blood microbiome together with metabolome profile between HCV-infected patients with CTP class B (CTP-B, significant functional compromise) and patients with CTP class A (CTP-A, well-compensated cirrhosis). METHODS: We conducted a cross-sectional study in patients with advanced HCV-related cirrhosis (n = 88) stratified by CTP-B and CTP-A. Bacterial 16S rRNA sequencing was sequenced by MiSeq Illumina technology and non-targeted metabolomics was performed by GC-MS and LC-MS ESI+ and ESI- to complement the analysis. RESULTS: Patients with CTP-B had lower levels of richness (Chao1), and alpha diversity (Shannon and Simpson indexes) at phylum level than patients with CTP-A. Likewise, we observed significant differences in beta diversity between groups at phylum, class, and order levels, showing lower diversity in patients with CTP-B. Higher relative abundance of Proteobacteria (p = 0.012), Alphaproteobacteria (p = 0.005), Sphingomonadales (p = 0.012) and Sphingomonadaceae (p = 0.016) were significantly associated with CTP-B. The phylum Proteobacteria was positively correlated with ethanolamine and oleic acid (p = 0.005 and p = 0.004, respectively) and negatively with p-cresol (p = 0.006). In addition, the order Sphingomonadales and the family Sphingomonadaceae was also negatively correlated with p-cresol (p = 0.001 and p = 0.001). CONCLUSIONS: Blood microbial diversity was significantly decreased in patients with CTP-B, who presented an enrichment of Proteobacteria, Alphaproteobacteria, Sphingomonadales and Sphingomonadaceae compared to patients with CTP-A.

Protection against fibrosis by a bacterial consortium in metabolic dysfunction-associated steatohepatitis and the role of amino acid metabolism.

The gut microbiota drives progression to liver fibrosis, the main determinant of mortality in metabolic dysfunction-associated steatohepatitis (MASH). In this study, we aimed to identify bacterial species associated with protection against liver fibrosis in a high-risk population, and test their potential to protect against liver fibrosis in vivo. Based on stool shotgun metagenomic sequencing of 340 subjects from a population cohort disproportionally affected by MASH, we identified bacterial species from the Bacteroidales and Clostridiales orders associated with reduced risk of liver fibrosis. A bacterial consortium was subsequently tested in a mouse model of MASH, which demonstrated protective effects against liver fibrosis. Six of the eight inoculated bacteria were detected in mouse stool and liver. Intrahepatic presence of bacteria was further confirmed by bacterial culture of mouse liver tissue. Changes in liver histological parameters, gut functional profiles, and amino acid profiles were additionally assessed. Comparison between fibrosis-associated human metagenome and bacteria-induced metagenome changes in mice identified microbial functions likely to mediate the protective effect against liver fibrosis. Amino acid profiling confirmed an increase in cysteine synthase activity, associated with reduced fibrosis. Other microbiota-induced changes in amino acids associated with reduced fibrosis included increased gut asparaginase activity and decreased hepatic tryptophan-to-kynurenine conversion. This human-to-mouse study identified bacterial species and their effects on amino acid metabolism as innovative strategies to protect against liver fibrosis in MASH.

Firmicutes/Bacteroidetes and Firmicutes/Proteobacteria ratios are associated with worse prognosis in a cohort of Latin American patients with cirrhosis.

BACKGROUND: Some evidence suggests an association between gut dysbiosis and cirrhosis progression. The authors investigated Gut Microbiome (GM) influence on 90-day mortality and hospitalization/rehospitalization rates in cirrhotic patients. METHODS: Compensated/decompensated outpatients and decompensated inpatients were prospectively included and compared to healthy controls. Clinical, laboratory, GM, and two ratios between phyla were evaluated. Patients were followed up for 90 days for hospitalization/rehospitalization and mortality. RESULTS: 165 individuals were included (50 compensated, 49 decompensated outpatients; 36 decompensated inpatients; 30 healthy), 48.5 % female, mean age was 61, main cirrhosis etiology was hepatitis C (27.3 %), and mostly Child-Pugh (CP) B patients, median MELD of 13. As liver disease progressed, microbiota diversity decreased between the groups (p = 0.05; p < 0.004). There were 9 deaths and 22 hospitalizations or rehospitalizations. GM composition had correlation with norfloxacin (p = 0.36, p = 0.04), encephalopathy (p = 0.31, p = 0.01), lactulose (p = 0.26, p = 0.01), 90-day mortality (p = 0.22, p = 0.04), CP (p = 0.17, p = 0.01), previous 6-month antibiotic use (p = 0.16, p = 0.01), MELD (p = 0.145, p = 0.01), ALBI (p = 0.1, p = 0.04) and 90-day hospitalization/rehospitalization (p = 0.08, p = 0.03). Firmicutes/Bacteroidetes (F/B) and Firmicutes/Proteobacteria (F/P) ratios were progressively lower and more significant and had an association with 90-day mortality (p < 0.001). Three MELD set-points (≥ 15, 18 and 20) were significantly associated with both ratios, with similar accuracies. CONCLUSIONS: GM dysbiosis was associated with higher CP, MELD, 90-day mortality and hospitalization/rehospitalization. F/B and F/P ratios were associated with 90-day mortality.

Gut microbiome profiles to exclude the diagnosis of hepatic encephalopathy in patients with cirrhosis.

Patients with cirrhosis who have cognitive complaints are presumed to have hepatic encephalopathy (HE), which leads to unwarranted medications while ignoring the underlying disease process causing these complaints. Since neuropsychological testing, the current gold standard for HE diagnosis, is not readily available, an orderable test is needed. We aimed to develop and validate a rapid gut microbiota test to exclude HE and determine stakeholder input on this approach. Stool was collected from two cohorts: a two-center training cohort (n = 305, on/not on HE-related therapy) and a multicenter validation cohort (n = 30, on HE treatment). Stool microbiota was analyzed rapidly using nanopore analysis. Stakeholder (patients and clinicians) needs assessment was evaluated using semi-quantitative questionnaires. In the training cohort, machine learning using neural network identified a 20-species signature that differentiated HE vs no-HE with 84% specificity compared to the gold standard neuropsychological testing. This high specificity persisted regardless of whether patients were on HE-related therapy or not. In the validation cohort, application of this profile led to reevaluation of the HE diagnosis and treatment in > 40% of the patients. This approach was acceptable to patients (Veterans in the validation cohort) and clinician (n = 40 nationwide) stakeholders. We conclude that a machine learning stool signature based on 20 microbial species developed in a training set and validated in a separate multicenter prospective cohort differentiated those with vs. without HE, identified patients misdiagnosed with HE, and was acceptable to patients and clinician stakeholders.

Alterations in the gut microbiome after transjugular intrahepatic portosystemic shunt in patients with hepatitis B virus-related portal hypertension.

BACKGROUND: Gut microbiota (GM) affects the progression and response to treatment in liver diseases. The GM composition is diverse and associated with different etiologies of liver diseases. Notably, alterations in GM alterations are observed in patients with portal hypertension (PH) secondary to cirrhosis, with hepatitis B virus (HBV) infection being a major cause of cirrhosis in China. Thus, understanding the role of GM alterations in patients with HBV infection-related PH is essential. AIM: To evaluate GM alterations in patients with HBV-related PH after transjugular intrahepatic portosystemic shunt (TIPS) placement. METHODS: This was a prospective, observational clinical study. There were 30 patients (with a 100% technical success rate) recruited in the present study. Patients with esophagogastric variceal bleeding due to HBV infection-associated PH who underwent TIPS were enrolled. Stool samples were obtained before and one month after TIPS treatment, and GM was analyzed using 16S ribosomal RNA amplicon sequencing. RESULTS: One month after TIPS placement, 8 patients developed hepatic encephalopathy (HE) and were assigned to the HE group; the other 22 patients were assigned to the non-HE group. There was no substantial disparity in the abundance of GM at the phylum level between the two groups, regardless of TIPS treatment (all, P > 0.05). However, following TIPS placement, the following results were observed: (1) The abundance of Haemophilus and Eggerthella increased, whereas that of Anaerostipes, Dialister, Butyricicoccus, and Oscillospira declined in the HE group; (2) The richness of Eggerthella, Streptococcus, and Bilophila increased, whereas that of Roseburia and Ruminococcus decreased in the non-HE group; and (3) Members from the pathogenic genus Morganella appeared in the HE group but not in the non-HE group. CONCLUSION: Intestinal microbiota-related synergism may predict the risk of HE following TIPS placement in patients with HBV-related PH. Prophylactic microbiome therapies may be useful for preventing and treating HE after TIPS placement.

Metagenomic comparison of intestinal microbiota between normal and liver fibrotic rhesus macaques (Macaca mulatta).

Liver fibrosis is an important pathological process in chronic liver disease and cirrhosis. Recent studies have found a close association between intestinal microbiota and the development of liver fibrosis. To determine whether there are differences in the intestinal microbiota between rhesus macaques with liver fibrosis (MG) and normal rhesus macaques (MN), fecal samples were collected from 8 male MG and 12 male MN. The biological composition of the intestinal microbiota was then detected using 16S rRNA gene sequencing. The results revealed statistically significant differences in ASVs and Chao1 in the alpha-diversity and the beta-diversity of intestinal microbiota between MG and MN. Both groups shared Prevotella and Lactobacillus as common dominant microbiota. However, beneficial bacteria such as Lactobacillus were significantly less abundant in MG (P = 0.02). Predictive functional analysis using PICRUSt2 gene prediction revealed that MG exhibited a higher relative abundance of functions related to substance transport and metabolic pathways. This study may provide insight into further exploration of the mechanisms by which intestinal microbiota affect liver fibrosis and its potential future use in treating liver fibrosis.

Gut microbiota and metabolites of cirrhotic portal hypertension: a novel target on the therapeutic regulation.

BACKGROUND: The regulatory role of gut microbiota and gut-derived metabolites through the gut-liver axis in the development of cirrhotic portal hypertension (PH) has received increasing attention. METHODS: The review summarized a series of investigations on effects of metabolites derived from microbiota and medicines targeting microbiome including rifaximin, VSL#3, statins, propranolol, FXR agonists as well as drugs derived from bile acids (BAs) on PH progression. RESULTS: Patients with PH exhibit alterations in gut microbial richness and differential overall microbiota community, and several results clearly displayed the correlation of PH with enrichment of Veillonella dispar or depletion of Clostridiales, Peptostreptococcaceae, Alistipes putredinis, Roseburia faecis and Clostridium cluster IV. The gut-derived metabolites including hydrogen sulfide, tryptophan metabolites, butyric acid, secondary BAs and phenylacetic acid (PAA) participate in a range of pathophysiology process of PH through modulating intrahepatic vascular resistance and portal blood flow associated with the formation and progression of PH. Established and emerging drugs targeting on bacterial translocation and intestinal eubiosis are gradually identified as potential strategies for treatments of liver cirrhosis and PH by modulating intestinal inflammation, splanchnic arterial vasodilation and endothelial dysfunction. CONCLUSIONS: Future explorations should further characterize the alteration of the fecal microbiome and metabolite profiles in PH and elucidate the regulatory mechanism of the intestinal microbiome, gut-derived metabolites and gut microbiota targeted pharmaceutical treatments involved in PH.

Role of gut/liver metabolites and gut microbiota in liver fibrosis caused by cholestasis.

AIM OF THE STUDY: Cholestasis induces severe liver injury and subsequent liver fibrosis. However, a comprehensive understanding of the relationships between liver fibrosis and cholestasis-induced changes in metabolites in the gut and fibrotic liver tissue and in the gut microbiota is insufficient. METHODS: Common bile duct ligation (BDL) was employed to establish a cholestatic liver fibrosis model in mice for 26 days. Fibrotic liver tissue and the gut contents were collected. Untargeted metabolomics was conducted for the determination of metabolites in the gut contents and liver tissues. Metagenomics was adopted to explore the gut microbiota. RESULTS: The metabolites in the gut contents and liver tissues between normal and cholestatic liver fibrosis mice were highly distinct. Beta-alanine metabolism and glutathione metabolism were downregulated in the gut of the BDL group. Galactose metabolism, biosynthesis of unsaturated fatty acids, and ABC transporters were upregulated in the gut and downregulated in the liver of the BDL group. Arginine biosynthesis, taurine and hypotaurine metabolism, arginine and proline metabolism, and primary bile acid biosynthesis were downregulated in the gut and upregulated in the liver of the BDL group. Metagenomic analysis revealed that the alpha diversity of the microbiota in the BDL group decreased. The altered structure of the gut microbiota in the BDL group led to the hypofunction of important metabolic pathways (such as folate biosynthesis, histidine metabolism, thiamine metabolism, biotin metabolism, and phenylalanine, tyrosine and tryptophan biosynthesis) and enzymes (such as NADH, DNA helicase, and DNA-directed DNA polymerase). Correlation analyses indicated that certain gut microbes were associated with gut and liver metabolites. CONCLUSIONS: Untargeted metabolomics and metagenomics provided comprehensive information on gut and liver metabolism and gut microbiota in mice with cholestatic liver fibrosis. Therefore, significantly altered bacteria and metabolites may help provide some targets against cholestatic liver fibrosis in the future.

The gut microbiota-bile acid axis in cholestatic liver disease.

Cholestatic liver diseases (CLD) are characterized by impaired normal bile flow, culminating in excessive accumulation of toxic bile acids. The majority of patients with CLD ultimately progress to liver cirrhosis and hepatic failure, necessitating liver transplantation due to the lack of effective treatment. Recent investigations have underscored the pivotal role of the gut microbiota-bile acid axis in the progression of hepatic fibrosis via various pathways. The obstruction of bile drainage can induce gut microbiota dysbiosis and disrupt the intestinal mucosal barrier, leading to bacteria translocation. The microbial translocation activates the immune response and promotes liver fibrosis progression. The identification of therapeutic targets for modulating the gut microbiota-bile acid axis represents a promising strategy to ameliorate or perhaps reverse liver fibrosis in CLD. This review focuses on the mechanisms in the gut microbiota-bile acids axis in CLD and highlights potential therapeutic targets, aiming to lay a foundation for innovative treatment approaches.

Exploring the diagnostic potential of immunoglobulin A-microbiota interplay in liver cirrhosis and spontaneous bacterial peritonitis.

The human gut microbiota significantly impacts health, including liver conditions like liver cirrhosis (LC) and spontaneous bacterial peritonitis (SBP). Immunoglobulin A (IgA) plays a central role in maintaining gut microbial balance. Understanding IgA's interplay with gut microbiota and liver health is crucial. This study explores the relationship between fecal IgA levels, gut microbiota, and liver injury severity. A total of 69 LC patients and 30 healthy controls were studied. Fecal IgA levels were measured using ELISA, and IgA-coated bacteria were quantified via flow cytometry. Microbiota diversity and composition were assessed through 16S rRNA sequencing. Liver injury severity was graded using the Child-Pugh score. Statistical analyses determined correlations. LC patients had higher fecal IgA levels than controls, correlating positively with liver injury severity. Microbiota diversity decreased with severity, accompanied by shifts in composition favoring pro-inflammatory species. Ralstonia abundance positively correlated with liver injury, whereas Faecalibacterium showed a negative correlation. Specific microbial markers for SBP were identified. Functional profiling revealed altered microbial functionalities in LC and SBP. Elevated fecal IgA levels, coupled with microbiota alterations, correlate with liver injury severity in LC patients. Modulating gut microbiota could be a promising strategy for managing liver-related conditions. Further research is needed to understand underlying mechanisms and translate findings into clinical practice, potentially improving patient outcomes.

Distinct Gut Microbial Signature and Host Genetic Variants in Association with Liver Fibrosis Severity in Patients with MASLD.

Gut microbiota might affect the severity and progression of metabolic dysfunction-associated steatotic liver disease (MASLD). We aimed to characterize gut dysbiosis and clinical parameters regarding fibrosis stages assessed by magnetic resonance elastography. This study included 156 patients with MASLD, stratified into no/mild fibrosis (F0-F1) and moderate/severe fibrosis (F2-F4). Fecal specimens were sequenced targeting the V4 region of the 16S rRNA gene and analyzed using bioinformatics. The genotyping of PNPLA3, TM6SF2, and HSD17B13 was assessed by allelic discrimination assays. Our data showed that gut microbial profiles between groups significantly differed in beta-diversity but not in alpha-diversity indices. Enriched Fusobacterium and Escherichia_Shigella, and depleted Lachnospira were found in the F2-F4 group versus the F0-F1 group. Compared to F0-F1, the F2-F4 group had elevated plasma surrogate markers of gut epithelial permeability and bacterial translocation. The bacterial genera, PNPLA3 polymorphisms, old age, and diabetes were independently associated with advanced fibrosis in multivariable analyses. Using the Random Forest classifier, the gut microbial signature of three genera could differentiate the groups with high diagnostic accuracy (AUC of 0.93). These results indicated that the imbalance of enriched pathogenic genera and decreased beneficial bacteria, in association with several clinical and genetic factors, were potential contributors to the pathogenesis and progression of MASLD.

Application of metagenomic next-generation sequencing in optimizing the diagnosis of ascitic infection in patients with liver cirrhosis.

BACKGROUND: Metagenomic next-generation sequencing (mNGS) is an emerging technique for the clinical diagnosis of infectious disease that has rarely been used for the diagnosis of ascites infection in patients with cirrhosis. This study compared mNGS detection with conventional culture methods for the on etiological diagnosis of cirrhotic ascites and evaluated the clinical effect of mNGS. METHODS: A total of 109 patients with ascites due to cirrhosis were included in the study. We compared mNGS with conventional culture detection by analyzing the diagnostic results, pathogen species and clinical effects. The influence of mNGS on the diagnosis and management of ascites infection in patients with cirrhosis was also evaluated. RESULTS: Ascites cases were classified into three types: spontaneous bacterial peritonitis (SBP) (16/109, 14.7%), bacterascites (21/109, 19.3%) and sterile ascites (72/109, 66.1%). In addition, 109 patients were assigned to the ascites mNGS-positive group (80/109, 73.4%) or ascites mNGS-negative group (29/109, 26.6%). The percentage of positive mNGS results was significantly greater than that of traditional methods (73.4% vs. 28.4%, P < 0.001). mNGS detected 43 strains of bacteria, 9 strains of fungi and 8 strains of viruses. Fourteen bacterial strains and 3 fungal strains were detected via culture methods. Mycobacteria, viruses, and pneumocystis were detected only by the mNGS method. The mNGS assay produced a greater polymicrobial infection rate than the culture method (55% vs. 16%). Considering the polymorphonuclear neutrophil (PMN) counts, the overall percentage of pathogens detected by the two methods was comparable, with 87.5% (14/16) in the PMN ≥ 250/mm3 group and 72.0% (67/93) in the PMN < 250/mm3 group (P > 0.05). Based on the ascites PMN counts combined with the mNGS assay, 72 patients (66.1%) were diagnosed with ascitic fluid infection (AFI) (including SBP and bacterascites), whereas based on the ascites PMN counts combined with the culture assay, 37 patients (33.9%) were diagnosed with AFI (P < 0.05). In 60 (55.0%) patients, the mNGS assay produced positive clinical effects; 40 (85.7%) patients had their treatment regimen adjusted, and 48 patients were improved. The coincidence rate of the mNGS results and clinical findings was 75.0% (60/80). CONCLUSIONS: Compared with conventional culture methods, mNGS can improve the detection rate of ascites pathogens, including bacteria, viruses, and fungi, and has significant advantages in the diagnosis of rare pathogens and pathogens that are difficult to culture; moreover, mNGS may be an effective method for improving the diagnosis of ascites infection in patients with cirrhosis, guiding early antibiotic therapy, and for reducing complications related to abdominal infection. In addition, explaining mNGS results will be challenging, especially for guiding the treatment of infectious diseases.

Prevalence and predictors of multidrug-resistant bacteremia in liver cirrhosis.

BACKGROUND/AIMS: Improved knowledge of local epidemiology and predicting risk factors of multidrug-resistant (MDR) bacteria are required to optimize the management of infections. This study examined local epidemiology and antibiotic resistance patterns of liver cirrhosis (LC) patients and evaluated the predictors of MDR bacteremia in Korea. METHODS: This was a retrospective study including 140 LC patients diagnosed with bacteremia between January 2017 and December 2022. Local epidemiology and antibiotic resistance patterns and the determinants of MDR bacteremia were analyzed using logistic regression analysis. RESULTS: The most frequently isolated bacteria, from the bloodstream, were Escherichia coli (n = 45, 31.7%) and Klebsiella spp. (n = 35, 24.6%). Thirty-four isolates (23.9%) were MDR, and extended-spectrum beta-lactamase E. coli (52.9%) and methicillin-resistant Staphylococcus aureus (17.6%) were the most commonly isolated MDR bacteria. When Enterococcus spp. were cultured, the majority were MDR (MDR 83.3% vs. 16.7%, p = 0.003), particularly vancomycin-susceptible Enterococcus faecium. Antibiotics administration within 30 days and/or nosocomial infection was a significant predictor of MDR bacteremia (OR: 3.40, 95% CI: 1.24-9.27, p = 0.02). MDR bacteremia was not predicted by sepsis predictors, such as positive systemic inflammatory response syndrome (SIRS) or quick Sequential Organ Failure Assessment (qSOFA). CONCLUSION: More than 70% of strains that can be treated with a third-generation cephalosporin have been cultured. In cirrhotic patients, antibiotic administration within 30 days and/or nosocomial infection are predictors of MDR bacteremia; therefore, empirical administration of broad-spectrum antibiotics should be considered when these risk factors are present.

Clinical evaluation of droplet digital pcr for suspected ascites infection in patients with liver cirrhosis.

BACKGROUND: Droplet digital PCR (ddPCR) is increasingly used in diagnosing clinical pathogens, but its effectiveness in cirrhosis patients with suspected ascites infection remains uncertain. METHODS: The diagnostic performance of ddPCR was assessed in 305 ascites samples, utilizing culture and clinical composite standards. The quantitative value and potential clinical impact of ddPCR were further analyzed in patients with spontaneous bacterial peritonitis. RESULTS: With culture standards, ddPCR demonstrated a sensitivity of 86.5% and specificity of 83.2% for bacterial or fungal detection. After adjustment of clinical composite criteria, specificity increased to 96.4%. Better diagnostic performance for all types of targeted pathogens, particularly fungi, was observed with ddPCR compared to culture, and more polymicrobial infections were detected (30.4% versus 5.7%, p < 0.001). Pathogen loads detected by ddPCR correlated with white blood cell count in ascites and blood, as well as polymorphonuclear cell (PMN) count in ascites, reflecting infection status rapidly. A positive clinical impact of 55.8% (43/77) was observed for ddPCR, which was more significant among patients with PMN count ≤ 250/mm3 in terms of medication adjustment and new diagnosis. ddPCR results for fungal detection were confirmed by clinical symptoms and other microbiological tests, which could guide antifungal therapy and reduce the risk of short-term mortality. CONCLUSIONS: ddPCR, with appropriate panel design, has advantages in pathogen detection and clinical management of ascites infection, especially for patients with fungal and polymicrobial infections. Patients with atypical spontaneous bacterial peritonitis benefited more from ddPCR.

Virological response to nucleos(t)ide analogues treatment in chronic hepatitis B patients is associated with Bacteroides-dominant gut microbiome.

BACKGROUND: Gut dysbiosis is present in chronic hepatitis B virus (HBV) infection. In this study, we integrated microbiome and metabolome analysis to investigate the role of gut microbiome in virological response to nucleos(t)ide analogues (NAs) treatment. METHODS: Chronic HBV patients were prospectively recruited for steatosis and fibrosis assessments via liver elastography, with full-length 16S sequencing performed to identify the compositional gut microbiota differences. Fasting plasma bile acids were quantified by liquid chromatography-tandem mass spectrometry. FINDINGS: All patients (n = 110) were characterized into three distinct microbial clusters by their dominant genus: c-Bacteroides, c-Blautia, and c-Prevotella. Patients with c-Bacteroides had a higher plasma ursodeoxycholic acids (UDCA) level and an increase in 7-alpha-hydroxysteroid dehydrogenase (secondary bile acid biotransformation) than other clusters. In NAs-treated patients (n = 84), c-Bacteroides was associated with higher odds of plasma HBV-DNA undetectability when compared with non-c-Bacteroides clusters (OR 3.49, 95% CI 1.43-8.96, p = 0.01). c-Blautia was positively associated with advanced fibrosis (OR 2.74, 95% CI 1.09-7.31, p = 0.04). No such associations were found in treatment-naïve patients. Increased Escherichia coli relative abundance (0.21% vs. 0.03%, p = 0.035) was found in on-treatment patients (median treatment duration 98.1 months) with advanced fibrosis despite HBV DNA undetectability. An enrichment in l-tryptophan biosynthesis was observed in patients with advanced fibrosis, which exhibited a positive correlation with Escherichia coli. INTERPRETATION: Collectively, unique bacterial signatures, including c-Bacteroides and c-Blautia, were associated with virological undetectability and fibrosis evolution during NAs therapy in chronic HBV, setting up intriguing possibilities in optimizing HBV treatment. FUNDING: This study was supported by the Guangdong Natural Science Fund (2019A1515012003).

Liver cirrhosis and antibiotic therapy but not TIPS application leads to a shift of the intestinal bacterial communities: A controlled, prospective study.

OBJECTIVES: The gut-liver axis is discussed to play an important role in hepatic cirrhosis. Decompensated liver cirrhosis is associated with portal hypertension, which can lead to a variety of complications. Transjugular intrahepatic portosystemic shunt (TIPS) is an established treatment option for the complications of portal hypertension. In this study we focused on the effect of TIPS on intestinal microbial composition in cirrhotic patients. METHODS: Thirty patients with liver cirrhosis were compared to 18 healthy adults. Seventeen patients with cirrhosis and portal hypertension received a TIPS. Clinical characteristics, including age, sex, and liver function measured with a Child-Pugh score and model for end-stage liver disease score, were obtained. Intestinal microbial composition was assessed via 16S rRNA gene amplicon sequencing from stool probes before and after TIPS. RESULTS: TIPS led to a reduction of hepatic venous pressure gradient. However, TIPS did not cause a shift in the intestinal bacterial communities. Independent from the application of TIPS, antibiotic therapy was associated with a significant difference in the intestinal bacterial microbiota and also a reduced α-diversity. In addition, a significant difference was observed in the intestinal bacterial composition between patients with liver cirrhosis and healthy controls. CONCLUSION: The presence of liver cirrhosis and the use of antibiotic therapy, but not the application of TIPS, were associated with a significant shift of the intestinal bacterial communities, showing a high impact on the microbiota of patients with liver cirrhosis.

Ascitic microbiota alteration is associated with portal vein tumor thrombosis occurrence and prognosis in hepatocellular carcinoma.

Portal vein tumor thrombosis (PVTT) frequently leads to malignant ascites (MA) in individuals with hepatocellular carcinoma (HCC), remaining a bottleneck in the treatment. This study aimed to explore the differences in microbes in paired groups and provide novel insights into PVTT and MA-related treatments. Formalin-fixed paraffin embedding ascite samples were collected from MA secondary to HCC and benign ascites (BA) secondary to liver cirrhosis (LC). Ascitic microbiota profiles were determined in the HCC and LC groups by 16S rRNA sequencing. Prognostic risk factors were screened using survival analysis. The correlation between the significantly different microbial signatures in the groups with PVTT (WVT) and non-PVTT (NVT) and clinical characteristics was explored. The expression of different immune cells was determined by labeling four markers in the MA tissue chips using multiplex immunohistochemistry. A total of 240 patients (196 with HCC with MA and 44 with LC with BA) were included in this study. Microbial profiles differed between the HCC and LC groups. PVTT and Barcelona Clinic Liver Cancer stage were shown to be prognostic risk factors. Significant differences in the alpha and beta diversities were observed between the WVT and NVT groups. Gammaproteobacteria and Acinetobacter were the most abundant in the HCC MA. Differences in microbial signatures between the WVT and NVT groups were correlated with the level of C-reactive protein and apolipoprotein A1. This study revealed the microbial differences in the tumor microenvironment of MA secondary to HCC and BA secondary to LC.IMPORTANCEFirst, we explored the alteration of the ascites ecosystem through the microbiota in patients with hepatocellular carcinoma (HCC) and liver cirrhosis. Second, this is the first clinical study to investigate the differences between patients with HCC with and without portal vein tumor thrombosis via 16S rRNA sequencing. These results revealed a decreased microbial diversity and metabolic dysregulation in individuals with HCC and portal vein tumor thrombosis. Gammaproteobacteria and Acinetobacter were the most abundant in the HCC malignant ascitic fluid. Our study provides a new perspective on treating malignant ascites secondary to HCC.

Alteration of Gut Microbiota Composition in the Progression of Liver Damage in Patients with Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD).

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a complex disorder whose prevalence is rapidly growing in South America. The disturbances in the microbiota-gut-liver axis impact the liver damaging processes toward fibrosis. Gut microbiota status is shaped by dietary and lifestyle factors, depending on geographic location. We aimed to identify microbial signatures in a group of Chilean MASLD patients. Forty subjects were recruited, including healthy controls (HCs), overweight/obese subjects (Ow/Ob), patients with MASLD without fibrosis (MASLD/F-), and MASLD with fibrosis (MASLD/F+). Both MASLD and fibrosis were detected through elastography and/or biopsy, and fecal microbiota were analyzed through deep sequencing. Despite no differences in α- and ß-diversity among all groups, a higher abundance of Bilophila and a lower presence of Defluviitaleaceae, Lachnospiraceae ND3007, and Coprobacter was found in MASLD/F- and MASLD/F+, compared to HC. Ruminococcaceae UCG-013 and Sellimonas were more abundant in MASLD/F+ than in Ow/Ob; both significantly differed between MASLD/F- and MASLD/F+, compared to HC. Significant positive correlations were observed between liver stiffness and Bifidobacterium, Prevotella, Sarcina, and Acidaminococcus abundance. Our results show that MASLD is associated with changes in bacterial taxa that are known to be involved in bile acid metabolism and SCFA production, with some of them being more specifically linked to fibrosis.