incretin

noun

in·​cre·​tin in-ˈkrē-tᵊn 

: any of various gastrointestinal hormones that stimulate the secretion of insulin by the pancreas

The actions of incretins depend on glucose concentration, and their function ceases when serum glucose level is less than 55 mg/dL …

—Renee E. Amori et al., The Journal of the American Medical Association

… ingested nutrients stimulate the release of gut peptides called incretins, which enhance secretion of the hormone insulin, the main controller of blood glucose levels.

—Joshua P. Thaler and David E. Cummings, Nature