Gut feelings about diabetes.

Studies of patients going into diabetes remission after gastric bypass surgery have demonstrated the important role of the gut in glucose control. The improvement of type 2 diabetes after gastric bypass surgery occurs via weight dependent and weight independent mechanisms. The rapid improvement of glucose levels within days after the surgery, in relation to change of meal pattern, rapid nutrient transit, enhanced incretin release and improved incretin effect on insulin secretion, suggest mechanisms independent of weight loss. Alternatively, insulin sensitivity improves over time as a function of weight loss. The role of bile acids and microbiome in the metabolic improvement after bariatric surgery remains to be determined. While most patients after bariatric surgery experienced sustained weight loss and improved metabolism, small scale studies have shown weight regain and diabetes relapse, the mechanisms of which remain unknown.