Inclusion Criteria:  Subject having signed the informed consent Male or female, 18 to 65 years of age Body Mass Index (BMI) greater than or equal to 25 kg/m²  Exclusion Criteria:  Pregnant woman (positive serum pregnancy test for selection) or breastfeeding, Infected subject under anti-retroviral treatment Subject with severe hepatic and / or renal insufficiency (awaiting transplant) Subject with anemia <10 g / dl Subject with known gastrointestinal illness Subject having undergone bariatric surgery Subject with a weight loss > 10% of body weight during the last 3 months (special diet: low calorie diet (slimming diet), special diet (vegetarians, vegans, nutritional supplements) before treatment), Subject taking pro or prebiotics before treatment Subject having taken antibiotics in the 2 months preceding inclusion Subject participating in another clinical study, Subject not enrolled in the French national healthcare system Subject not compliing with the exclusion period from the study in which he/she has previously participated