The Effect of Bariatric Surgery on Metabolism, the Metabolome and Microbiome in Patients With Type 2 Diabetes
Condition: Type 2 Diabetes Mellitus; Obesity
MeSH terms: Diabetes Mellitus; Diabetes Mellitus, Type 2
Study type: Interventional
Phase: Phase 2

Summary: 
      What are the benefits of undergoing Roux-en-Y gastric bypass surgery in improving type 2
      diabetes outside of weight loss alone?
    

Detailed description: 
      Roux-en-y gastric bypass (RYGB) surgery leads to improvements in diabetes that occurs even
      before any significant weight loss is seen. What are the reasons for this? There is evidence
      in animals that changes in the composition of gut bacteria after RYGB may be responsible for
      improvements in how glucose is metabolized in the body. The study aims to correlate changes
      in the bacterial composition of the gut that occurs after surgery with improvements in
      glucose metabolism in people with type 2 diabetes. The investigators will do this by using
      validated methods to measure glucose metabolism and cutting edge technology to analyze the
      gut microbiome. A parallel group of patients with similar weight, height and age will undergo
      caloric restriction alone to mimic weight loss seen after RYGB. Participants will also
      undergo similar glucose metabolism studies and analysis of their gut bacterial composition.
      Thus, any difference seen between groups can be attributed to the surgery itself and may lead
      to identification of novel therapeutic options for diabetes.
    

Intervention name(s): Roux-en-Y Gastric Bypass (RYGB); Caloric Restriction; Exendin-9,39; Normal Saline
Intervention type(s): Procedure; Behavioral; Drug; Drug
Intervention description(s): Subjects will be studied prior to surgical intervention and 12 weeks post surgery. Subjects in surgical arm will start diet intervention after surgery. Follow up with dietary will be per standard of care following RYGB surgery.; Subjects participating in caloric arm of this study will be asked to consume an identical diet that is controlled for caloric content and macronutrient composition. This is identical to that consumed by patient undergoing RYGB. Subjects in the caloric restriction arm will start the diet after the screening visit. Compliance will be monitored by alternating weekly meetings with a clinical psychologist and dietician.; A subset of 4 subjects who have undergone RYGB surgery will be studied 4 weeks after surgery. Subjects will be randomized to receive an infusion of either Exendin-9,39 or normal saline. Exendin-9,39 blocks the action of specific hormones called "incretins" that are produced by the gut in health and in larger quantities after gastric bypass surgery.; subset of 4 subjects who have undergone RYGB surgery will be studied 4 weeks after surgery. Subjects will be randomized to receive an infusion of either Exendin-9,39 or normal saline. Exendin-9,39 blocks the action of specific hormones called "incretins" that are produced by the gut in health and in larger quantities after gastric bypass surgery.
Other intervention name(s): Bariatric Surgery
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Bariatric Surgery; Weight loss