Comparative Effects of Bile Diversion and Duodenal-Jejunal Bypass on Glucose and Lipid Metabolism in Male Diabetic Rats.

Abstract

Duodenal-jejunal bypass (DJB) induces rapid and durable improvement in glucose and lipid metabolism. Besides bypassing the proximal gut, DJB also diverts bile acids (BAs) into the distal gut, increasing luminal and systemic BAs that are essential to metabolic homeostasis. The aim of this study is to evaluate whether bile diversion (BD) alone can recapitulate the effects of DJB on glucose and lipid metabolism. BD, DJB and SHAM procedures were performed in a diabetic rat model induced by high-fat diet (HFD)/streptozotocin (STZ). Body weight, energy intake, blood glucose, serum hormones, insulin sensitivity, lipid profiles, and luminal and systemic BAs were measured postsurgery. BD reduced body weight, independently of energy intake, whereas DJB had no effects. Luminal and serum BAs were increased after both DJB and BD, and were higher after BD than DJB. During glucose tolerance test, both fasting and postprandial blood glucose concentrations were reduced with DJB and BD, and were lower after DJB than BD. Insulin sensitivity was improved after DJB, but remained unchanged after BD. Fasting and postprandial GLP-1 were equally increased after DJB and BD. Serum triglyceride and free fatty acids were decreased more after BD than DJB, while hepatic triglyceride storage was reduced more after DJB. These observations indicate that BD, which increases luminal and systemic BAs and postprandial GLP-1, represents an important component of DJB in restoring glucose and lipid homeostasis in diabetic state. However, other mechanisms associated with DJB also appear to make complementary contributions to metabolic regulation.