Most patients who undergo Roux-en-Y gastric bypass (RYGB) experience rapid resolution of type 2 diabetes. Prior studies indicate that this results from more than gastric restriction and weight loss, implicating the rearranged intestine as a primary mediator. In this lecture, Dr. Francesco Rubino endeavors to give an explanation to this evidence, showing the results of his studies in Goto-Kakizaki lean, diabetic rats.