CCK and diabetes mellitus: However, there is a growing body of evidence that there are significant beneficial changes in gastric physiology, including altered neurohumoral signaling resulting in decreased serum levels of ghrelin, a hormone known to stimulate the hunger reflex, increases in serum cholecystokinin (CCK) that stimulates insulin secretion, increased GIP, GLP1, and GLP2 which play key roles in diabetes resolution and metabolic control, and microbial ecology that may alter the Gut-Brain axis, factors that are all thought to contribute to weight loss and metabolic benefits following surgery [11–13].