Gut check: could your microbiome be key to obesity and diabetes?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Aged between 18 and 60 years. * Ability to understand and provide informed consent. * Ability and willingness to meet the required schedule and study interventions. * Willingness to share their community belonging * Benefit from a social security system. For obese and diabetic patients : * IMC ≥ 30 kg/m² with type 2 diabetes * Fasting plasma glucose (FPG) ≥7 mM (=1.26g/l) or * Patients with HbA1c ≥ 6.5% (48 mmol/mol) * All stages of albuminuria For obese patients without type 2 diabetes * IMC ≥ 30 kg/m² * Weight stable for at least 2 months * Patients with normal glucose tolerance (NGT), impaired glucose tolerance (IGT) and/or impaired fasting glucose (IFG) and an HbA1c \< 6.5 % * No treatment (diabetic or weight loss) * Match age (±5years), sex and self-reported community to the patients from the1 group. For control group : * BMI between 18.5-24.9 kg/m² * Match age (±5years), sex and self-reported community to the patients from the 1 and 2 groups. * Participants with normal glucose tolerance (NGT), impaired glucose tolerance (IGT) and/or impaired fasting glucose (IFG) and an HbA1c \< 6.5 % Exclusion Criteria: All participants : * Treatment that may alter gastrointestinal motor function, acidity, microbial population, or immunosuppressants * Altered anatomy of the esophagus, stomach, small intestine, or large intestine due to gastrointestinal surgery (except appendectomy or cholecystectomy) * Chronic or acute inflammatory bowel disease or infections * Abdominal or pelvic radiation therapy or abdominal cancer, colorectal cancer * Dysphagia, eosinophilic esophagitis, esophageal stricture, or other swallowing disorders * Organ transplantation and patients receiving immunosuppressive therapy * Severe renal failure and/or patients undergoing dialysis * Cardiovascular, endocrine, renal, or other chronic disease that may affect motility. * Preparation for colon cleansing within the last month * \< 3 bowel movements per week * Women who are pregnant or breastfeeding