Changes in Glucose Homeostasis after Roux-en-Y Gastric Bypass Surgery for Obesity at Day Three, Two Months, and One Year after Surgery: Role of Gut Peptides.
"Endocrine effects of gastric bypass (GBP) surgery for obesity on glucose homeostasis are not fully understood."
"Both enhanced insulin sensitivity and incretin hormones, such as GLP-1, contribute to the early control of glucose homeostasis. Progressively increasing postprandial levels of enteroglucagon (oxyntomodulin) and GLP-1 facilitate weight loss and enhance insulin effectiveness."
Serum bile acids are higher in humans with prior gastric bypass: potential contribution to improved glucose and lipid metabolism.
It has also been suggested that poor and slow bile acid secretion in obese people is responsible for poor GLP-1 secretions.
In this study the authors speculate that the higher concentration of blood bile acids is enforced by increased bile acid uptake by the ileum because it is moved closer to the entrance from the stomach.
"Post-GB anatomic or functional adaptive changes, including altered dietary patterns, intestinal motility, mucosal hyperplasia, or gut flora, could each contribute to increased postprandial bile acid absorption."