Crosstalk Between Mucosal-Associated Invariant T (MAIT) Cells and the Gut Microbiota and Mucosa in the Development of Type 1 Diabetes in Children

Inclusion Criteria: Recent onset group * age \> 12 months and \< 15 years * recently diagnosed type 1 diabetes according ISPAD criteria At risk subjects: * age \> 12 months and \< 15 years * siblings of type 1 diabetic patient * HLA DR3 and DR4 positive Control subjects: * age \> 12 months and \< 15 years * no HLA associated with high risk type 1 diabetes * no antibodies against pancreas antigenes Control subjects for UGI endoscopy: * age \> 12 months and \< 15 years * suspicion of coeliac disease or gastritis Exclusion Criteria: For all groups: * no health care insurance * parents or tutors unable to sign the consent * personal history of autoimmune disease and/or inflammatory disease except from T1D for RD and CE groups * use of corticosteroids during the month before inclusion * pregnant subjects * medical contraindication of anesthetic topics For control subjects for UGI endoscopy control and Recent onset-endoscopy group: * age below 8 years for Recent onset-endoscopy group * age below 4 for UGI endoscopy control group * cardiac or respiratory insufficiency, cardiac rhythm disorders, coagulation disease, patients treated with anticoagulant or antiaggregant drug * history of allergy to anesthetic drug