In a population of patients with Non Alcoholic Fatty Liver Disease (NAFLD), the investigators will compare the composition of the gut microbiota from patients with simple steatosis with that with steatohepatitis.

The purpose of this study is to determine if the pathogenic Escherichia Coli to the B2 group and producing the genotoxin colibactin is a factor for developing NASH.

Gut microbiota composition is now linked to the onset of obesity, metabolic disorders, and Non Alcoholic Fatty Liver Disease . While simple steatosis has benign prognosis, steatohepatitis (NASH) leads to cirrhosis and hepatocarcinoma and increases cardiovascular and cancer- related mortality. Some Escherichia coli (E. coli) belonging to the B2 phylogenetic group are involved in many diseases. Those producing the genotoxin colibactin are in addition known to induce a chronic alteration of intestinal permeability, one of the major factors leading to NASH.

Inclusion Criteria:

• NAFLD
• indication of liver biopsy

Exclusion Criteria:

• presence of any other cause of liver or steatosis
• alcohol consumption exceeding 30 g / day for a men and 20 g / day for a woman
• a history of decompensated cirrhosis
• treatment with prebiotics, probiotics or antibiotics in the month prior to inclusion
• chronic gastrointestinal disease or history of gastrointestinal surgery
• pregnancy or breastfeeding
• patient under guardianship

Patients with Non Alcoholic Fatty Liver Disease