The Role of the Duodenum in the Pathogenesis of Insulin Resistance and Type 2 Diabetes Mellitus

In parallel with the increasing prevalence of obesity worldwide, type 2 diabetes mellitus (T2DM) has reached epidemic proportions. Despite a multitude of available therapies, only bariatric surgery (e.g., roux-en-Y gastric bypass (GBP)) has proven to be an effective long term treatment modality for morbid obesity. Moreover, the majority of T2DM patients who undergo GBP experience normalization of their blood glucose and are able to discontinue their anti-diabetes medications soon after the procedure. The insulin resistant state commonly seen in non-diabetic obese subjects also improves after GBP. Evidence from recent animal studies suggests that the rapid return to euglycemia seen in T2DM patients after GBP might in part result from excluding the duodenum from the flow of nutrients. With the use of enteral feeding tubes, we hope to better understand the factors in the human gut that may predispose obese individuals to the development of insulin resistance and T2DM.