This study compared cholinergic-induced jejunal contractility and evaluated the effects of Glucagon like peptide-1 (GLP-1) and Gastric inhibitory polypeptide (GIP) in relation to the expression of these peptides, their receptors, and Dipeptidyl peptidase 4 (DPP-4) in jejunal muscle of obese patients with and without T2DM. This evidence concerns the gene GIP and type 2 diabetes mellitus.