Physiologic and Functional Adaptations of Insulin Sensitive Tissues

Upper endoscopy (subset) * Intestinal biopsies will be obtained during scheduled upper endoscopy from the mid-duodenum and/or proximal jejunum. In the case that a patient requires an upper endoscopy after metabolic and bariatric surgery, biopsies will be obtained from the mid-jejunum. * Blood will be collected from an IV placed in the arm used for administering anesthesia required for the indicated procedure. Colonoscopy (subset) * Biopsies of the colon will be obtained during scheduled colonoscopy. * Blood will be collected from an IV placed in the arm used for administering anesthesia required for the indicated procedure. Metabolic and bariatric surgery (subset) * During the metabolic and bariatric surgical procedures, biopsy of the jejunum, liver and omentum (visceral adipose) may be obtained. Biopsies of skeletal muscle and subcutaneous adipose will be taken at the sites of trocar placement for laparotomy. * Blood will be collected from an IV placed in the arm used for administering anesthesia required for the indicated procedure. * Feces will be self-collected by the patient using a provided culture swab specimen container or FOB card. Liver transplantation (subset) • Tissue will be collected from excised disease liver