The Role of Bacterial Products and Intestinal Microbiota in Non-alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) includes simple steatosis (SS) and non-alcoholic steatohepatitis (NASH), which can progress to cirrhosis. NAFLD pathogenesis is complex. Recent research suggests a role for the intestinal microbiota (IM) with various potential mechanisms involving bacterial metabolism and products. This cross-sectional study compared bacterial products and metabolites in the blood and feces, and fecal levels of total bacteria, Bacteroidetes, C. coccoides, C. leptum, Bifidobacteria, Lactobacilli, E. coli and Archaea in biopsy confirmed SS, NASH, and healthy controls (HC). NAFLD patients (SS+NASH) had higher levels of bacterial fecal metabolites, including choline, trimethylamine, total short-chain fatty acids, propionate, isobutyric acid, and higher serum 2-hydroxybutyrate than HC. NASH patients had lower proportions of fecal C. leptum and higher amounts of E. coli than HC. Several bacterial metabolites correlated with histological findings, and with specific bacteria and diet. These findings suggest a potential role for bacteria and bacterial metabolism in NAFLD pathogenesis.M.Sc