Type 2 diabetes mellitus (T2DM) is a relevant public health problem and obesity has been associated as the major risk factor. Roux-en-Y gastric bypass is an effective method to treat severe obesity, and its metabolic benefits can lead to early and complete remission of T2DM, even before a considerable weight loss. We have hypothesized that intestinal anatomic changes may change intestinal genes expression related to glycemic control. The knowledge of mechanisms mediating the glycemic control after Roux-en-Y gastric bypass and it site of action in bowel may eventually help to develop alternative, less invasive and safer surgery for the treatment of T2DM, as well as drug development for the newly targets identified.

Inclusion Criteria:

Type 2 diabetes mellitus (T2DM) diagnosis Duration of T2DM >5 years Use of oral antidiabetic agents Body Mass Index >40 kg/m2 Candidates to Roux-en-Y gastric bypass

Exclusion Criteria:

Type 1 diabetes mellitus or non-diabetics Use of insulin Thyroid diseases Candidate to other surgery technique Body Mass Index <40 kg/m2 Presence of bacterium H. Pylori

Severe obese patients with T2DM candidates to Roux-en-Y gastric bypass surgery