Jejunal Luminal and Colonic Mucosa-Associated Microbiota in Metabolic Diseases: Methods, Identification and Causalities (JE/COL-MIME)

1. Control Group 15 non-obese participants considered "metabolically-healthy" : "control group"
2. Obese group (Ob) 15 severely obese participants, candidates for bariatric surgery, but without T2D: "obese group" (Ob)
3. Obese and Type 2 Diabetes group (ObD) 15 participants who are both severely obese, candidates for bariatric surgergy and diagnosed with T2D: "obese and diabetic group" (ObD).

Inclusion Criteria:

• General Inclusion Criteria:

  • Aged between 18 and 60 years;
  • Ability to understand and provide informed consent (in French);
  • Ability and willingness to meet the required schedule and study procedures;
• Group-Specific Inclusion Criteria:
• Control Group

Inclusion criteria for the participants from the Control group are:

• Presence of Gastroesophageal Reflux Disease symptoms or gastric discomfort.
• BMI [19kg/m² < BMI <25 kg/m²]
• Match age and sex to the patients from the Ob and ObD groups.

• Only patients with normal glucose tolerance (NGT), glucose tolerance (IGT) and/or fasting glucose (IFG) and an HbA1c < 6.5 % will be included in this group.

  • Ob Group

Inclusion criteria for the participants from Ob and ObD groups are:

● Candidate for bariatric surgery and meet the HAS criteria (Haute Autorité de Santé, 2009) :

• IMC ≥ 40 kg/m² without comorbidities Or IMC≥ 35 kg/m² with at least one obesity-related comorbidity (i.e.: Hypertension, Dyslipidemia, Obstructive Sleep Apnea, Joints Disease, non-alcoholic steatohepatitis, excluding T2D)
• Weight stable for at least 2 months
• No treatment for metabolic health complications, no previous obesity surgery, no obesity treatment drug.

• No monogenic form of obesity (Hebebrand et al., 2017)

  • ObD Group

Inclusion criteria for the participants from ObD groups are:

• Candidate for bariatric surgery with T2D
• At least one obesity-related comorbidity including T2D
• Fasting plasma glucose (FPG) ≥7 mM (=1.26g/l) or
• Participants with HbA1c ≥ 6.5% (48 mmol/mol)
• All stages of albuminuria

Exclusion Criteria:

• General Non-inclusion Criteria:

  • Treatment for the previous 12 week that could

    • alter gastrointestinal motor function (e.g. opioids, prokinetics, anticholinergics, laxatives),
    • acidity (PPI, H2RA)
    • microbial population (e.g.: antibiotics, probiotics)
    • immunosuppressants (eg: calcineurin inhibitors, corticosteroids, biological agents, etc.).
    • use of weight-loss drug or dietary intervention aiming to lose weight;

  • Altered anatomy of the esophagus, stomach, small or large intestine due to prior gastrointestinal surgery (exceptions include appendectomy or cholecystectomy more than 3 months prior to enrollment) or other reasons;

    • Any abdominal or pelvic surgery within the past 3 months;
    • Diverticulitis, diverticular stricture, or other intestinal strictures.
    • Intestinal resection of the gastrointestinal tract
  • Previous history of gastric bezoar or gastroparesis
  • Acute or chronic inflammatory bowel disease or infections diseases (i.e.: VHC, VHB, VIH, etc.)
  • Abdominal or pelvic radiotherapy or abdominal cancer
  • Colorectal cancer, either known or not
  • Dysphagia, eosinophilic esophagitis, esophageal stricture, or other swallowing disorder
  • Organ Transplantation and patients on Immunosuppressive Therapy
  • Severe kidney failure and/or patients on dialysis therapy (serum creatinine > 150 μmol/l or eGFR < 60 ml/min per 1.73 m2 body surface area)
  • CVD, endocrine, renal or other chronic disease likely to affect motility.
  • Colon cleansing preparation during the last 1 month
  • No < 3 bowel movements per week
  • Females of childbearing age who do not practice birth control and/or are pregnant or lactating
  • Participants non-affiliated to the French national health scheme
  • Participants who are already included in a clinical study which implies testing any pharmaceutical drug.
  • Participants who do not understand the research procedures those who are institutionalized, or who unable to give informed consent
  • Participants placed under legal protection
  • Patients with drug addiction
  • Antibiotherapy 3 months preceding the endoscopy
  • Weight variation (diminution or increase) > 5kg in the last 3 months
• Specific non-inclusion Criteria

• Ob and ObT2D Group

  • Usual contraindication for bariatric surgery;