PMC

Taste receptors couple to G proteins upon activation to induce intracellular Ca²⁺ increase resulting in release of peptides, which regulate a variety of gastrointestinal functions, including action on organs associated with the gut like the gallbladder and pancreas, via neuronal or humoral pathways to induce digestion and absorption or protection from harmful substances. Released peptides can also control food intake through the gut–brain axis.

Putative sites of chemosensing are localized on the cell surface. When the luminal content (nutrients and non-nutrients) comes in contact with enteroendocrine cells, it induces release of hormones that enter blood vessels or signaling molecules that activate extrinsic or intrinsic afferent neurons thereby sending neuronal messages to the central nervous system and to enteric neurons. Released molecules can also act directly on adjacent cells, including other enteroendocrine cells and other types of epithelial cells like brush cells.