Characterization of the Digestive Functions and the Enteric Nervous System in Obesity. Investigations of Relationships With Metabolism Disorders(EnteroNeurObesity)

60 patients scheduled for bariatric surgery will be included into 3 categories (20 patients with non complicated obesity, 20 patients with metabolic syndrome and 20 patients with a type 2 diabetes or hypertension). 20 volunteers will be enrolled as normal referents. The patients and the volunteers will have a classical pre-operative check-up (fibroscopy, oesophageal pHmetry and manometry) and extra investigations as isotopic gastric empty exam, lactulose oro-caecal transit exam, intestinal permeability test calculated by lactulose-manitol ratio urinary excretion. Intestinal and colonic biopsies will be also provided for studying permeability. For only patients, samples from the gastric resection will be provided for analysing the enteric nervous system and motricity.