The Role of Bile After Roux-en-Y Gastric Bypass in Promoting Weight Loss and Improving Glycaemic Control

• Published in: Endocrinology (Philadelphia) Vol. 153; no. 8; pp. 3613 - 3619
• Main Authors: Pournaras, Dimitri J., Glicksman, Clare, Vincent, Royce P., Kuganolipava, Shophia, Alaghband-Zadeh, Jamie, Mahon, David, Bekker, Jan H.R., Ghatei, Mohammad A., Bloom, Stephen R., Walters, Julian R.F., Welbourn, Richard, le Roux, Carel W.
• Format: Journal Article
• Language: English
• Published: Chevy Chase, MD Oxford University Press 01.08.2012; Endocrine Society
• Subjects: Acids; Adult; Animal models; Animals; Bile; Bile - physiology; Bile acids; Bile Acids and Salts - blood; Biological and medical sciences; Blood Glucose - metabolism; Body weight; C-Reactive Protein; Calorimetry; Diabetes; Diabetes mellitus (non-insulin dependent); Diabetes Mellitus, Type 2; Diabetes-Insulin-Glucagon-Gastrointestinal; Dogs; Female; Fibroblast Growth Factors - blood; Food intake; Fundamental and applied biological sciences. Psychology; Gastric Bypass; Gastrointestinal surgery; Glucagon-Like Peptide 1 - blood; Growth factors; Humans; Ileum; Male; Middle Aged; Peptide YY - blood; Plasma; Rats; Rats, Wistar; Remission; Satiety; Small intestine; Vertebrates: endocrinology; Weight; Weight loss; Weight Loss - physiology; Biological fluid; Stomach; Digestive system; Bile
• ISSN: 0013-7227; 1945-7170; 1945-7170
• DOI: 10.1210/en.2011-2145

Gastric bypass leads to the remission of type 2 diabetes independently of weight loss. Our hypothesis is that changes in bile flow due to the altered anatomy may partly explain the metabolic outcomes of the operation. We prospectively studied 12 patients undergoing gastric bypass and six patients undergoing gastric banding over a 6-wk period. Plasma fibroblast growth factor (FGF)19, stimulated by bile acid absorption in the terminal ileum, and plasma bile acids were measured. In canine and rodent models, we investigated changes in the gut hormone response after altered bile flow. FGF19 and total plasma bile acids levels increased after gastric bypass compared with no change after gastric banding. In the canine model, both food and bile, on their own, stimulated satiety gut hormone responses. However, when combined, the response was doubled. In rats, drainage of endogenous bile into the terminal ileum was associated with an enhanced satiety gut hormone response, reduced food intake, and lower body weight. In conclusion, after gastric bypass, bile flow is altered, leading to increased plasma bile acids, FGF19, incretin. and satiety gut hormone concentrations. Elucidating the mechanism of action of gastric bypass surgery may lead to novel treatments for type 2 diabetes.