Gastrin is a hormone produced by 'G' cells in the stomach and upper small intestine, which is then released into the bloodstream.
Gastrin encourages the stomach to release gastric acid throughout a meal (hydrochloric acid). The stomach uses gastric acid to convert the inactive form of a protein digestion enzyme called pepsinogen into the active form of pepsin, which allows the stomach to break down proteins eaten as food and absorb specific vitamins like vitamin B12.
Gastrin is a peptide hormone that promotes the growth of gastric mucosa, motility, and the production of hydrochloric acid (HCl) in the stomach.
Gastric acid also serves as a disinfectant, killing the majority of germs and microbes that enter the stomach with food, reducing the chance of infection.
Gastrin can also cause the pancreas to produce enzymes and the gallbladder to empty its bile reserve.
Gastrin also helps digestion by stimulating stomach lining development and increasing gut muscle contractions.