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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/m(2): 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.

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.

BackgroundCurrent guidelines for clinical practice recommend the infusion of human albumin after large volume paracentesis. After inspecting the current evidence behind this recommendation, we decided to conduct a systematic review and meta-analysis in order to address the effect of albumin on mortality and morbidity in the context of large volume paracentesis. MethodsWe performed a comprehensive search of large databases and abstract books of conference proceedings up to March 15th 2016 for randomized controlled trials, testing the infusion of human albumin against alternatives (vs no treatment, vs plasma expanders; vs vasoconstrictors) in HCC-free patients suffering from cirrhosis. We analyzed these trials with regard to mortality, changes in plasma renin activity (PRA), hyponatremia, renal impairment, recurrence of ascites with consequential re-admission into hospital and additional complications. We employed trial sequential analysis in order to calculate the number of patients required in controlled trials to be able to determine a statistically significant advantage of the administration of one agent over another with regard to mortality. ResultsWe were able to include 21 trials totaling 1277 patients. While the administration of albumin prevents a rise in PRA as well as hyponatremia, no improvement in strong clinical endpoints such as mortality could be demonstrated. Trial sequential analysis showed that at least 1550 additional patients need to be recruited into RCTs and analyzed with regard to this question in order to detect or disprove a 25% mortality effect. ConclusionsThere is insufficient evidence that the infusion of albumin after LVP significantly lowers mortality in HCC-free patients with advanced liver disease.

Chronic infection with hepatitis C virus (HCV) is one of the main causes of hepatocellular carcinoma. However, the molecular mechanisms linking the infection to cancer development remain poorly understood. Here we used HCVinfected cells and liver biopsies to study how HCV modulates the glutaminolysis pathway, which is known to play an important role in cellular energetics, stress defense, and neoplastic transformation. Transcript levels of glutaminolytic factors were quantified in Huh7.5 cells or primary human hepatocytes infected with the Japanese fulminant hepatitis 1 HCV strain as well as in biopsies of chronic HCV patients. Nutrient deprivation, biochemical analysis, and metabolite quantification were performed with HCV-infected Huh7.5 cells. Furthermore, short hairpin RNA vectors and small molecule inhibitors were used to investigate the dependence of HCV replication on metabolic changes. We show that HCV modulates the transcript levels of key enzymes of glutamine metabolism in vitro and in liver biopsies of chronic HCV patients. Consistently, HCV infection increases glutamine use and dependence. We finally show that inhibiting glutamine metabolism attenuates HCV infection and the oxidative stress associated with HCV infection. Conclusion: Our data suggest that HCV establishes glutamine dependence, which is required for viral replication, and, importantly, that glutamine addiction is a hallmark of tumor cells. While HCV induces glutaminolysis to create an environment favorable for viral replication, it predisposes the cell to transformation. Glutaminolytic enzymes may be interesting therapeutic targets for prevention of hepatocarcinogenesis in chronic hepatitis C.

Nonalcoholic fatty liver disease (NAFLD) has emerged as the most common chronic liver disease worldwide with a reported prevalence ranging 6-33%, depending on the studied populations. It encompasses a spectrum of liver manifestations ranging from simple steatosis (also known as nonalcoholic fatty liver, NAFL) to nonalcoholic steatohepatitis (NASH), fibrosis and cirrhosis, which may ultimately progress to hepatocellular carcinoma. NAFLD is strongly associated with the components of metabolic syndrome, mainly obesity and type 2 diabetes mellitus. NAFLD patients are at increased risk of liver-related as well as cardiovascular mortality. Current paradigm suggests a benign course for NAFL whereas NASH is considered to be the progressive phenotype. Although previously under-recognized accumulating evidence suggests that NAFL may also progress, suggesting a higher number of patients at risk than previously appreciated. Liver biopsy remains the gold standard for definitive diagnosis, but the majority of patients can be diagnosed accurately by noninvasive methods. Approved therapies for NAFLD are still lacking and lifestyle modifications aiming at weight loss remain the mainstay of NAFLD treatment. Intensive research could identify insulin resistance, lipotoxicity and dysbiosis of the gut microbiota as major pathophysiological mechanisms, leading to the development of promising targeted therapies which are currently investigated in clinical trials. In this review we summarized the current knowledge of NAFLD epidemiology, natural history, diagnosis, pathogenesis and treatment and considered future directions.