I had the opportunity to present the results from one of my PhD studies conducted at Center for Diabetes Research, Gentofte Hospital. The current study examined the potential GLP-1 secretory effect of cholecystokinin-induced gallbladder emptying and concomitant single-dose metformin in patients with type 2 diabetes.
We found cholecystokinin-induced gallbladder emptying and the resulting release of bile acids to the gastrointestinal tract to elicit increased GLP-1 secretion. Concomitant single-dose metformin caused a further enhancement of GLP-1 secretion, whereas no GLP-1 secretory effect of metformin alone was observed.
Previous studies have demonstrated metformin to reduce the intestinal reabsorption of bile acids, and thus, our findings suggest metformin-induced GLP-1 secretion to involve modulation of the enterohepatic circulation of bile acids.