Bacteriophage targeting of gut bacterium attenuates alcoholic liver disease.

Chronic liver disease due to alcohol-use disorder contributes markedly to the global burden of disease and mortality1-3. Alcoholic hepatitis is a severe and life-threatening form of alcohol-associated liver disease. The gut microbiota promotes ethanol-induced liver disease in mice4, but little is known about the microbial factors that are responsible for this process. Here we identify cytolysin-a two-subunit exotoxin that is secreted by Enterococcus faecalis5,6-as a cause of hepatocyte death and liver injury. Compared with non-alcoholic individuals or patients with alcohol-use disorder, patients with alcoholic hepatitis have increased faecal numbers of E. faecalis. The presence of cytolysin-positive (cytolytic) E. faecalis correlated with the severity of liver disease and with mortality in patients with alcoholic hepatitis. Using humanized mice that were colonized with bacteria from the faeces of patients with alcoholic hepatitis, we investigated the therapeutic effects of bacteriophages that target cytolytic E. faecalis. We found that these bacteriophages decrease cytolysin in the liver and abolish ethanol-induced liver disease in humanized mice. Our findings link cytolytic E. faecalis with more severe clinical outcomes and increased mortality in patients with alcoholic hepatitis. We show that bacteriophages can specifically target cytolytic E. faecalis, which provides a method for precisely editing the intestinal microbiota. A clinical trial with a larger cohort is required to validate the relevance of our findings in humans, and to test whether this therapeutic approach is effective for patients with alcoholic hepatitis.

Any alcohol use in NAFLD patients is associated with significant changes to the intestinal virome.

BACKGROUND AND AIMS: The prevalence of alcohol use disorder (AUD) and metabolic dysfunction-associated fatty liver disease (MAFLD) are increasing worldwide, leading to the increasing likelihood of both etiologies contributing to a patient's liver disease. However, the effects of modest alcohol use in NAFLD are controversial and more studies are needed. We compared the intestinal viromes of patients with AUD and NAFLD in order to evaluate the effect of alcohol consumption on the intestinal viromes of NAFLD patients by extracting virus-like particles and performing metagenomic sequencing. APPROACH AND RESULTS: Viral nucleic acids were extracted from fecal samples and subjected to metagenomic sequencing. We demonstrate significant differences in the intestinal viromes of NAFLD and AUD patients, and that alcohol use in NAFLD patients reclassified to MAFLD accounted for significant differences in the intestinal viromes. The relative abundance of several Lactococcus phages was more similar between AUD patients and alcohol-consuming MAFLD patients than non-alcohol-consuming MAFLD patients and control subjects, and multivariate modeling using the most discriminating Lactococcus phages could better predict alcohol use in the MAFLD population than the alcohol-associated liver disease/NAFLD Index. Significant differences in the viral composition and diversity were also seen between MAFLD patients with low and moderate alcohol consumption compared with no alcohol consumption. CONCLUSIONS: The intestinal virome of MAFLD patients who consume low to moderate amounts of alcohol are significantly different from those who do not, and many features of the intestinal virome of alcohol-consuming MAFLD patients resemble that of AUD patients.

Hepatic pIgR-mediated secretion of IgA limits bacterial translocation and prevents ethanol-induced liver disease in mice.

OBJECTIVE: Alcohol-associated liver disease is accompanied by microbial dysbiosis, increased intestinal permeability and hepatic exposure to translocated microbial products that contribute to disease progression. A key strategy to generate immune protection against invading pathogens is the secretion of IgA in the gut. Intestinal IgA levels depend on the polymeric immunoglobulin receptor (pIgR), which transports IgA across the epithelial barrier into the intestinal lumen and hepatic canaliculi. Here, we aimed to address the function of pIgR during ethanol-induced liver disease. DESIGN: pIgR and IgA were assessed in livers from patients with alcohol-associated hepatitis and controls. Wild-type and pIgR-deficient (pIgR-/- ) littermates were subjected to the chronic-binge (NIAAA model) and Lieber-DeCarli feeding model for 8 weeks. Hepatic pIgR re-expression was established in pIgR-/- mice using adeno-associated virus serotype 8 (AAV8)-mediated pIgR expression in hepatocytes. RESULTS: Livers of patients with alcohol-associated hepatitis demonstrated an increased colocalisation of pIgR and IgA within canaliculi and apical poles of hepatocytes. pIgR-deficient mice developed increased liver injury, steatosis and inflammation after ethanol feeding compared with wild-type littermates. Furthermore, mice lacking pIgR demonstrated increased plasma lipopolysaccharide levels and more hepatic bacteria, indicating elevated bacterial translocation. Treatment with non-absorbable antibiotics prevented ethanol-induced liver disease in pIgR-/- mice. Injection of AAV8 expressing pIgR into pIgR-/- mice prior to ethanol feeding increased intestinal IgA levels and ameliorated ethanol-induced steatohepatitis compared with pIgR-/- mice injected with control-AAV8 by reducing bacterial translocation. CONCLUSION: Our results highlight that dysfunctional hepatic pIgR enhances alcohol-associated liver disease due to impaired antimicrobial defence by IgA in the gut.

Management of alcoholic hepatitis: A clinical perspective.

Alcohol-associated liver disease is the primary cause of liver-related mortality worldwide and one of the most common indications for liver transplantation. Alcoholic hepatitis represents the most acute and severe manifestation of alcohol-associated liver disease and is characterized by a rapid onset of jaundice with progressive inflammatory liver injury, worsening of portal hypertension, and an increased risk for multiorgan failure in patients with excessive alcohol consumption. Severe alcoholic hepatitis is associated with a poor prognosis and high short-term mortality. During the COVID-19 pandemic, rates of alcohol-associated hepatitis have increased significantly, underscoring that it is a serious and growing health problem. However, adequate management of alcohol-associated hepatitis and its complications in everyday clinical practice remains a major challenge. Currently, pharmacotherapy is limited to corticosteroids, although these have only a moderate effect on reducing short-term mortality. In recent years, translational studies deciphering key mechanisms of disease development and progression have led to important advances in the understanding of the pathogenesis of alcoholic hepatitis. Emerging pathophysiology-based therapeutic approaches include anti-inflammatory agents, modifications of the gut-liver axis and intestinal dysbiosis, epigenetic modulation, antioxidants, and drugs targeting liver regeneration. Concurrently, evidence is increasing that early liver transplantation is a safe treatment option with important survival benefits in selected patients with severe alcoholic hepatitis not responding to medical treatment. This narrative review describes current pathophysiology and management concepts of alcoholic hepatitis, provides an update on emerging treatment options, and focuses on the need for holistic and patient-centred treatment approaches to improve prognosis.

Fecal cytolysin does not predict disease severity in acutely decompensated cirrhosis and acute-on-chronic liver failure.

BACKGROUND: Cirrhosis with acute decompensation (AD) and acute-on-chronic liver failure (ACLF) are characterized by high morbidity and mortality. Cytolysin, a toxin from Enterococcus faecalis (E. faecalis), is associated with mortality in alcohol-associated hepatitis (AH). It is unclear whether cytolysin also contributes to disease severity in AD and ACLF. METHODS: We studied the role of fecal cytolysin in 78 cirrhotic patients with AD/ACLF. Bacterial DNA from fecal samples was extracted and real-time quantitative polymerase chain reaction (PCR) was performed. The association between fecal cytolysin and liver disease severity in cirrhosis with AD or ACLF was analyzed. RESULTS: Fecal cytolysin and E. faecalis abundance did not predict chronic liver failure (CLIF-C) AD and ACLF scores. Presence of fecal cytolysin was not associated with other liver disease markers, including Fibrosis-4 (FIB-4) index, 'Age, serum Bilirubin, INR, and serum Creatinine (ABIC)' score, Child-Pugh score, model for end-stage liver disease (MELD) nor MELD-Na scores in AD or ACLF patients. CONCLUSIONS: Fecal cytolysin does not predict disease severity in AD and ACLF patients. The predictive value of fecal cytolysin positivity for mortality appears to be restricted to AH.

The fecal mycobiome in non-alcoholic fatty liver disease.

BACKGROUND & AIMS: Studies investigating the gut-liver axis have largely focused on bacteria, whereas little is known about commensal fungi. We characterized fecal fungi in patients with non-alcoholic fatty liver disease (NAFLD) and investigated their role in a fecal microbiome-humanized mouse model of Western diet-induced steatohepatitis. METHODS: We performed fungal internal transcribed spacer 2 sequencing using fecal samples from 78 patients with NAFLD, 16 controls and 73 patients with alcohol use disorder. Anti-Candida albicans (C. albicans) IgG was measured in blood samples from 17 controls and 79 patients with NAFLD. Songbird, a novel multinominal regression tool, was used to investigate mycobiome changes. Germ-free mice were colonized with feces from patients with non-alcoholic steatohepatitis (NASH), fed a Western diet for 20 weeks and treated with the antifungal amphotericin B. RESULTS: The presence of non-obese NASH or F2-F4 fibrosis was associated with a distinct fecal mycobiome signature. Changes were characterized by an increased log-ratio for Mucor sp./Saccharomyces cerevisiae (S. cerevisiae) in patients with NASH and F2-F4 fibrosis. The C. albicans/S. cerevisiae log-ratio was significantly higher in non-obese patients with NASH when compared with non-obese patients with NAFL or controls. We observed a different fecal mycobiome composition in patients with NAFLD and advanced fibrosis compared to those with alcohol use disorder and advanced fibrosis. Plasma anti-C. albicans IgG was increased in patients with NAFLD and advanced fibrosis. Gnotobiotic mice, colonized with human NASH feces and treated with amphotericin B were protected from Western diet-induced steatohepatitis. CONCLUSIONS: Non-obese patients with NAFLD and more advanced disease have a different fecal mycobiome composition to those with mild disease. Antifungal treatment ameliorates diet-induced steatohepatitis in mice. Intestinal fungi could be an attractive target to attenuate NASH. LAY SUMMARY: Non-alcoholic fatty liver disease is one of the most common chronic liver diseases and is associated with changes in the fecal bacterial microbiome. We show that patients with non-alcoholic fatty liver disease and more severe disease stages have a specific composition of fecal fungi and an increased systemic immune response to Candida albicans. In a fecal microbiome-humanized mouse model of Western diet-induced steatohepatitis, we show that treatment with antifungals reduces liver damage.

Management of Dyslipidemia in Patients with Non-Alcoholic Fatty Liver Disease.

PURPOSE OF REVIEW: Patients with non-alcoholic fatty liver disease (NAFLD), often considered as the hepatic manifestation of the metabolic syndrome, represent a population at high cardiovascular risk and frequently suffer from atherogenic dyslipidemia. This article reviews the pathogenic interrelationship between NAFLD and dyslipidemia, elucidates underlying pathophysiological mechanisms and focuses on management approaches for dyslipidemic patients with NAFLD. RECENT FINDINGS: Atherogenic dyslipidemia in patients with NAFLD results from hepatic and peripheral insulin resistance along with associated alterations of hepatic glucose and lipoprotein metabolism, gut dysbiosis, and genetic factors. Since atherogenic dyslipidemia and NAFLD share a bi-directional relationship and are both major driving forces of atherosclerotic cardiovascular disease (ASCVD) development, early detection and adequate treatment are warranted. Thus, integrative screening and management programs are urgently needed. A stepwise approach for dyslipidemic patients with NAFLD includes (i) characterization of dyslipidemia phenotype, (ii) individual risk stratification, (iii) definition of treatment targets, (iv) lifestyle modification, and (v) pharmacotherapy if indicated.

Perinatal Obesity Induces Hepatic Growth Restriction with Increased DNA Damage Response, Senescence, and Dysregulated Igf-1-Akt-Foxo1 Signaling in Male Offspring of Obese Mice.

Maternal obesity predisposes for hepato-metabolic disorders early in life. However, the underlying mechanisms causing early onset dysfunction of the liver and metabolism remain elusive. Since obesity is associated with subacute chronic inflammation and accelerated aging, we test the hypothesis whether maternal obesity induces aging processes in the developing liver and determines thereby hepatic growth. To this end, maternal obesity was induced with high-fat diet (HFD) in C57BL/6N mice and male offspring were studied at the end of the lactation [postnatal day 21 (P21)]. Maternal obesity induced an obese body composition with metabolic inflammation and a marked hepatic growth restriction in the male offspring at P21. Proteomic and molecular analyses revealed three interrelated mechanisms that might account for the impaired hepatic growth pattern, indicating prematurely induced aging processes: (1) Increased DNA damage response (γH2AX), (2) significant upregulation of hepatocellular senescence markers (Cdnk1a, Cdkn2a); and (3) inhibition of hepatic insulin/insulin-like growth factor (IGF)-1-AKT-p38-FoxO1 signaling with an insufficient proliferative growth response. In conclusion, our murine data demonstrate that perinatal obesity induces an obese body composition in male offspring with hepatic growth restriction through a possible premature hepatic aging that is indicated by a pathologic sequence of inflammation, DNA damage, senescence, and signs of a possibly insufficient regenerative capacity.

Intestinal Virome Signature Associated With Severity of Nonalcoholic Fatty Liver Disease.

BACKGROUND & AIMS: Alterations in the gut microbiome have been associated with the severity of nonalcoholic fatty liver disease (NAFLD). Previous studies focused exclusively on the bacteria in the microbiome; we investigated changes in the viral microbiome (virome) in patients with NAFLD. METHODS: In a prospective, cross-sectional, observational study, we extracted RNA and DNA virus-like particles from fecal samples from 73 patients with NAFLD: 29 patients had an NAFLD Activity Score (NAS) of 0-4, 44 patients had an NAS of 5-8 or liver cirrhosis (LCI), 37 patients had F0-F1 fibrosis, and 36 patients had F2-F4 fibrosis. As controls, 9 individuals without liver disease and 13 patients with mild primary biliary cholangitis were included in the analysis. We performed shotgun metagenomic sequencing of virus-like particles. RESULTS: Patients with NAFLD and NAS 5-8/LCI had a significant decrease in intestinal viral diversity compared with patients with NAFLD and NAS 0-4 or control individuals. The presence of more advanced NAFLD was associated with a significant reduction in the proportion of bacteriophages compared with other intestinal viruses. Using multivariate logistic regression analysis with leave-1-out cross validation, we developed a model, including a viral diversity index and simple clinical variables, that identified patients with NAS 5-8/LCI with an area under the curve of 0.95 (95% confidence interval, 0.91-0.99) and F2-F4 fibrosis with an area under the curve of 0.88 (95% confidence interval, 0.80-0.95). Addition of data on viral diversity significantly improved multivariate models, including those based on only clinical parameters or bacterial diversity. CONCLUSIONS: In a study of fecal viromes from patients with NAFLD and control individuals, we associated histologic markers of NAFLD severity with significant decreases in viral diversity and proportion of bacteriophages. We developed a model based on fecal viral diversity and clinical data that identifies patients with severe NAFLD and fibrosis more accurately than models based only on clinical or bacterial data.

Intestinal Fungal Dysbiosis and Systemic Immune Response to Fungi in Patients With Alcoholic Hepatitis.

Chronic alcohol consumption causes increased intestinal permeability and changes in the intestinal microbiota composition, which contribute to the development and progression of alcohol-related liver disease. In this setting, little is known about commensal fungi in the gut. We studied the intestinal mycobiota in a cohort of patients with alcoholic hepatitis, patients with alcohol use disorder, and nonalcoholic controls using fungal-specific internal transcribed spacer amplicon sequencing of fecal samples. We further measured serum anti-Saccharomyces cerevisiae antibodies (ASCA) as a systemic immune response to fungal products or fungi. Candida was the most abundant genus in the fecal mycobiota of the two alcohol groups, whereas genus Penicillium dominated the mycobiome of nonalcoholic controls. We observed a lower diversity in the alcohol groups compared with controls. Antibiotic or steroid treatment was not associated with a lower diversity. Patients with alcoholic hepatitis had significantly higher ASCA levels compared to patients with alcohol use disorder and to nonalcoholic controls. Within the alcoholic hepatitis cohort, patients with levels of at least 34 IU/mL had a significantly lower 90-day survival (59%) compared with those with ASCA levels less than 34 IU/mL (80%) with an adjusted hazard ratio of 3.13 (95% CI, 1.11-8.82; P = 0.031). Conclusion: Patients with alcohol-associated liver disease have a lower fungal diversity with an overgrowth of Candida compared with controls. Higher serum ASCA was associated with increased mortality in patients with alcoholic hepatitis. Intestinal fungi may serve as a therapeutic target to improve survival, and ASCA may be useful to predict the outcome in patients with alcoholic hepatitis.

Intestinal Virome in Patients With Alcoholic Hepatitis.

BACKGROUND AND AIMS: Alcoholic hepatitis (AH) is a severe manifestation of alcohol-associated liver disease (ALD) with high mortality. Although gut bacteria and fungi modulate disease severity, little is known about the effects of the viral microbiome (virome) in patients with ALD. APPROACH AND RESULTS: We extracted virus-like particles from 89 patients with AH who were enrolled in a multicenter observational study, 36 with alcohol use disorder (AUD), and 17 persons without AUD (controls). Virus-like particles from fecal samples were fractionated using differential filtration techniques, and metagenomic sequencing was performed to characterize intestinal viromes. We observed an increased viral diversity in fecal samples from patients with ALD, with the most significant changes in samples from patients with AH. Escherichia-, Enterobacteria-, and Enterococcus phages were over-represented in fecal samples from patients with AH, along with significant increases in mammalian viruses such as Parvoviridae and Herpesviridae. Antibiotic treatment was associated with higher viral diversity. Specific viral taxa, such as Staphylococcus phages and Herpesviridae, were associated with increased disease severity, indicated by a higher median Model for End-Stage Liver Disease score, and associated with increased 90-day mortality. CONCLUSIONS: In conclusion, intestinal viral taxa are altered in fecal samples from patients with AH and associated with disease severity and mortality. Our study describes an intestinal virome signature associated with AH.

Combined analysis of gut microbiota, diet and PNPLA3 polymorphism in biopsy-proven non-alcoholic fatty liver disease.

BACKGROUND AND AIMS: Non-alcoholic fatty liver disease (NAFLD) is a global health burden. Risk factors for disease severity include older age, increased body mass index (BMI), diabetes, genetic variants, dietary factors and gut microbiota alterations. However, the interdependence of these factors and their individual impact on disease severity remain unknown. METHODS: In this cross-sectional study, we performed 16S gene sequencing using fecal samples, collected dietary intake, PNPLA3 gene variants and clinical and liver histology parameters in a well-described cohort of 180 NAFLD patients. Principal component analyses were used for dimensionality reduction of dietary and microbiota data. Simple and multiple stepwise ordinal regression analyses were performed. RESULTS: Complete data were available for 57 NAFLD patients. In the simple regression analysis, features associated with the metabolic syndrome had the highest importance regarding liver disease severity. In the multiple regression analysis, BMI was the most important factor associated with the fibrosis stage (OR per kg/m2 : 1.23, 95% CI 1.10-1.37, P < .001). The PNPLA3 risk allele had the strongest association with the histological grade of steatosis (OR 5.32, 95% CI 1.56-18.11, P = .007), followed by specific dietary patterns. Low abundances of Faecalibacterium, Bacteroides and Prevotella and high abundances of Gemmiger were associated with the degree of inflammation, ballooning and stages of fibrosis, even after taking other cofactors into account. CONCLUSIONS: BMI had the strongest association with histological fibrosis, but PNPLA3 gene variants, gut bacterial features and dietary factors were all associated with different histology features, which underscore the multifactorial pathogenesis of NAFLD.

The Candida albicans exotoxin candidalysin promotes alcohol-associated liver disease.

BACKGROUND & AIMS: Alcohol-associated liver disease is a leading indication for liver transplantation and a leading cause of mortality. Alterations to the gut microbiota contribute to the pathogenesis of alcohol-associated liver disease. Patients with alcohol-associated liver disease have increased proportions of Candida spp. in the fecal mycobiome, yet little is known about the effect of intestinal Candida on the disease. Herein, we evaluated the contributions of Candida albicans and its exotoxin candidalysin in alcohol-associated liver disease. METHODS: C. albicans and the extent of cell elongation 1 (ECE1) were analyzed in fecal samples from controls, patients with alcohol use disorder and those with alcoholic hepatitis. Mice colonized with different and genetically manipulated C. albicans strains were subjected to the chronic-plus-binge ethanol diet model. Primary hepatocytes were isolated and incubated with candidalysin. RESULTS: The percentages of individuals carrying ECE1 were 0%, 4.76% and 30.77% in non-alcoholic controls, patients with alcohol use disorder and patients with alcoholic hepatitis, respectively. Candidalysin exacerbates ethanol-induced liver disease and is associated with increased mortality in mice. Candidalysin enhances ethanol-induced liver disease independently of the ß-glucan receptor C-type lectin domain family 7 member A (CLEC7A) on bone marrow-derived cells, and candidalysin does not alter gut barrier function. Candidalysin can damage primary hepatocytes in a dose-dependent manner in vitro and is associated with liver disease severity and mortality in patients with alcoholic hepatitis. CONCLUSIONS: Candidalysin is associated with the progression of ethanol-induced liver disease in preclinical models and worse clinical outcomes in patients with alcoholic hepatitis. LAY SUMMARY: Candidalysin is a peptide toxin secreted by the commensal gut fungus Candida albicans. Candidalysin enhances alcohol-associated liver disease independently of the ß-glucan receptor CLEC7A on bone marrow-derived cells in mice without affecting intestinal permeability. Candidalysin is cytotoxic to primary hepatocytes, indicating a direct role of candidalysin on ethanol-induced liver disease. Candidalysin might be an effective target for therapy in patients with alcohol-associated liver disease.

Cytolysin-positive Enterococcus faecalis is not increased in patients with non-alcoholic steatohepatitis.

Several studies show associations between gut bacterial dysbiosis and chronic liver diseases, but causative mechanisms are largely unclear. We recently identified cytolysin, a bacterial exotoxin expressed and secreted by Enterococcus faecalis to cause liver damage in the setting of alcohol-related liver disease. Cytolysin was increased and highly correlated with liver disease severity and mortality in alcoholic hepatitis patients. In this study, we investigated if faecal cytolysin-positivity can be linked to non-alcoholic fatty liver disease, a highly prevalent disease where new biomarkers and treatment targets are urgently needed. In contrast to what we observed in alcoholic hepatitis, only seven out of 96 non-alcoholic fatty liver disease patients were cytolysin-positive, and these patients did not have increased liver disease activity compared with cytolysin-negative patients. These results indicate that the association of cytolysin carriage with worse clinical outcome might be specific for alcoholic hepatitis.

Hepatocellular carcinoma surveillance with liver imaging is not associated with improved survival.

Objective: International guidelines recommend hepatocellular carcinoma (HCC) surveillance with ultrasound in high-risk patients with chronic liver diseases. However, there is low-strength evidence about the effects on mortality. The aim of our study was to assess the impact of surveillance on the clinical course and survival of HCC patients seen at a tertiary referral center in Germany.Material and methods: We retrospectively evaluated the data of 401 HCC patients, who presented to our clinic between 1997 and 2015. Two groups were compared regarding patient and disease outcomes: one group included patients who received at least two ultrasound examinations for surveillance purposes prior to first diagnosis (n = 111). The other group consisted of patients with HCC at first presentation without foregoing HCC surveillance (n = 290).Results: Median follow-up in the surveillance group was 76 months (range 4-310 months). Patients in the surveillance group had smaller median tumor sizes (3.5 cm vs. 4.5 cm; p < .001), fulfilled more often Milan criteria (64% vs. 42%; p < .001) and received more often liver transplantation (27% vs. 9%, p < .001) when compared with the non-surveillance group. However, HCC surveillance was not associated with an improved survival (14 months in the surveillance group vs. 12 months in the non-surveillance group, p = .375), hazard ratio regarding overall mortality for the surveillance group: 0.80 (95% CI: 0.62-1.04, p = .09).Conclusions: HCC surveillance with ultrasound led to the detection of earlier disease stages but was not significantly associated with improved survival. Further prospective and long-term studies are needed to clarify benefits and harms of HCC surveillance programs on mortality.

Phenotyping non-alcoholic fatty liver disease by the gut microbiota: Ready for prime time?

BACKGROUND AND AIM: Several studies observed alterations in the gut microbiota in patients with non-alcoholic fatty liver disease (NAFLD). However, analyzed patient populations and methods strongly differ among these studies. The aim of this study was to prove the reproducibility of published results and to provide a detailed overview of all findings in our NAFLD cohort using next generation sequencing methods. METHODS: The individual taxonomic microbiota composition of fecal samples from 90 NAFLD patients and 21 healthy controls was analyzed using 16S rRNA gene sequencing. Study participants were grouped according to their disease stage and compared regarding their gut microbiota composition. Studies were identified from PubMed listed publications, and the results were compared with the findings in our cohort. RESULTS: Results from 13 identified studies were compared with our data. A decreased abundance of the Bacteroidetes and Ruminococcaceae as well as an increased abundance of Lactobacillaceae and Veillonellaceae and Dorea were the most frequently reported changes among NAFLD patients in 4/13, 5/13, 4/13, 2/13, and 3/13 studies, respectively. Even though these alterations in the gut microbiota composition were also observed in our patient cohort, the majority of published differences could not be reproduced, neither in our own nor in other NAFLD cohort studies. CONCLUSION: Despite repeatedly reproduced abundance patterns of specific bacteria, the heterogeneous study results did not reveal a consistent disease specific gut microbiota signature. Further prospective studies with homogenous patient cohorts and standardized methods are necessary to phenotype NAFLD by the gut microbiota.

Transcriptomic Profiling Identifies Novel Hepatic and Intestinal Genes Following Chronic Plus Binge Ethanol Feeding in Mice.

BACKGROUND: Alcohol-associated liver disease accounts for half of cirrhosis-related deaths worldwide. The spectrum of disease varies from simple steatosis to fibrosis, cirrhosis and ultimately hepatocellular carcinoma. Understanding the disease on a molecular level helps us to develop therapeutic targets. AIM: We performed transcriptomic analysis in liver and ileum from chronic plus binge ethanol-fed mice, and we assessed the role of selected differentially expressed genes and their association with serum bile acids and gut microbiota. METHODS: Wild-type mice were subjected to a chronic Lieber-DeCarli diet model for 8 weeks followed by one binge of ethanol. RNA-seq analysis was performed on liver and ileum samples. Associations between selected differentially regulated genes and serum bile acid profile or fecal bacterial profiling (16S rDNA sequencing) were investigated. RESULTS: We provide a comprehensive transcriptomic analysis to identify differentially expressed genes, KEGG pathways, and gene ontology functions in liver and ileum from chronic plus binge ethanol-fed mice. In liver, we identified solute carrier organic anion transporter family, member 1a1 (Slco1a1; encoding for organic anion transporting polypeptides (OATP) 1A1), as the most down-regulated mRNA, and it is negatively correlated with serum cholic acid level. Prokineticin 2 (Prok2) mRNA, a cytokine-like molecule associated with gastrointestinal tract inflammation, was significantly down-regulated in ethanol-fed mice. Prok2 mRNA expression was negatively correlated with abundance of Allobaculum (genus), Coprococcus (genus), Lachnospiraceae (family), Lactococcus (genus), and Cobriobacteriaceae (family), while it positively correlated with Bacteroides (genus). CONCLUSIONS: RNA-seq analysis revealed unique transcriptomic signatures in the liver and intestine following chronic plus binge ethanol feeding.

Serum and Fecal Oxylipins in Patients with Alcohol-Related Liver Disease.

BACKGROUND: Alcohol-related liver disease is one of the most prevalent chronic liver diseases worldwide. Mechanisms involved in the pathogenesis of alcohol-related liver disease are not well understood. Oxylipins play a crucial role in numerous biological processes and pathological conditions. Nevertheless, oxylipins are not well studied in alcohol-related liver disease. AIMS: (1) To characterize the patterns of bioactive ω-3 and ω-6 polyunsaturated fatty acid metabolites in alcohol use disorder and alcoholic hepatitis patients and (2) to identify associations of serum oxylipins with clinical parameters in patients with alcohol-related liver disease. METHODS: We performed a comprehensive liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis of serum and fecal oxylipins derived from ω-6 arachidonic acid, ω-3 eicosapentaenoic acid, and docosahexaenoic acid in a patient cohort with alcohol-related liver disease. RESULTS: Our results show profound alterations in the serum oxylipin profile of patients with alcohol use disorder and alcoholic hepatitis compared to nonalcoholic controls. Spearman correlation of the oxylipins with clinical parameters shows a link between different serum oxylipins and intestinal permeability, aspartate aminotransferase, bilirubin, albumin, international normalized ratio, platelet count, steatosis, fibrosis and model for end-stage liver disease score. Especially, higher level of serum 20-HETE was significantly associated with decreased albumin, increased hepatic steatosis, polymorphonuclear infiltration, and 90-day mortality. CONCLUSIONS: Patients with alcohol-related liver disease have different oxylipin profiles. Future studies are required to confirm oxylipins as disease biomarker or to connect oxylipins to disease pathogenesis.

Detection of clinically relevant serrated polyps during screening colonoscopy: results from seven cooperating centers within the German colorectal screening program.

BACKGROUND: Serrated polyps have been recognized as precursors of colorectal cancer (CRC) via the serrated pathway. Endoscopic detection and histopathological evaluation of serrated polyps are challenging. The aims of this study were to determine detection rates of the recently proposed entity of clinically relevant serrated polyps (crSPs) and to identify factors that influence their detection in a primary colonoscopy screening cohort. METHODS: We retrospectively analyzed average-risk screening colonoscopies performed at a tertiary academic hospital and six community-based private practices in Germany between 01/01/2012 and 14/12/2016. Exclusion criteria were age < 50 years, conditions with increased risk for CRC (e. g. inflammatory bowel disease, history of CRC, hereditary cancer syndromes), and incomplete procedures. CrSPs were defined as serrated polyps ≥ 10 mm and/or > 5 mm located proximally to the splenic flexure. Conventional adenomas were defined as adenomas excluding serrated polyps. RESULTS: A total of 4161 colonoscopies from average-risk individuals were included (median age 62 years [interquartile range 56 - 69]; 48.6 % male). CrSPs were detected in 6.9 %, with a mean detection rate of 4.7 % (95 % confidence interval 2.3 % - 7.2 %). Detection rates ranged from 0 % to 16.2 %. In multivariate analysis, simultaneous detection of conventional adenomas and an endoscopist adenoma detection rate of ≥ 25 % were significantly associated with increased detection of crSPs, with odds ratios of 1.43 (95 %CI 1.11 - 1.85; P = 0.01) and 7.35 (95 %CI 4.43 - 12.19; P < 0.001). The individual endoscopist's detection rate for conventional adenomas and crSPs were significantly correlated (r = 0.54, P = 0.02). CONCLUSION: Detection rates for crSPs differed between participating endoscopists. However, individual skills to detect polypoid lesions have a relevant bearing on the detection rate of crSPs.

Hyperplastic polyps and nonadvanced adenomas, but not advanced polypoid lesions, are detected more frequently in the presence of colonic diverticula during screening colonoscopies.

HINTERGRUND: Die bisher veröffentlichte Studienlage zur Assoziation von Kolondivertikeln und kolorektalen Polypen einschließlich des kolorektalen Karzinoms (KRK) ist konträr. Ziel der Studie war es, die Assoziation für sämtliche relevanten histologischen Polypensubtypen, d. h. hyperplastische Polypen (HP), sessil und traditionell serratierte Adenome (SSA und TSA), klinisch relevante serratierte Polypen (krSP), tubuläre Adenome und fortgeschrittene Adenome in einer ausschließlichen Vorsorgekoloskopie-Kohorte zu untersuchen. MATERIAL UND METHODEN: Wir führten eine retrospektive Analyse von Personen ≥ 50 Jahre und einem durchschnittlichen Risiko für ein KRK, die eine Vorsorgekoloskopie zwischen dem 01.01.2012 und dem 14.12.2016 in einer Universitätsklinik und 6 gastroenterologischen Schwerpunktpraxen erhalten haben, durch. Ausschlusskriterien waren Erkrankungen mit einem erhöhten KRK-Risiko (z. B. chronisch-entzündliche Darmerkrankungen, KRK in der Vorgeschichte, hereditäre Karzinomsyndrome), eine vorherige Koloskopie und eine unvollständige Untersuchung. ERGEBNISSE: 4196 Koloskopien wurden eingeschlossen (mittleres Alter 63,4 Jahre, Standardabweichung ±â€Š7,6 Jahre, 48,6 %). Bei Vorliegen von Divertikeln zeigten sich nach Adjustierung für Alter und Geschlecht erhöhte Odds-Ratios (OR) für den Nachweis von HP im gesamten (OR 1,340, 95 %-Konfidenzintervall 1,133 - 1,584, p = 0,001) und im distalen Kolon (OR 1,459, 95 %-KI 1,208 - 1,763, p < 0,001) sowie von tubulären Adenomen im distalen Kolon (OR 1,355, 95 %-KI 1,144 - 1,604, p < 0,001). Die mittlere Polypenanzahl pro Untersuchung mit dem Nachweis von mindestens einem Polypensubtypen unterschied sich nicht zwischen beiden Gruppen. SCHLUSSFOLGERUNG: Die Untersucher sollten beim Vorliegen einer Divertikulose wachsam für den Nachweis von vor allem distal gelegenen Adenomen sein.