When the food you have eaten reaches the stomach, the hormone released is what we call Gastrin. The ‘G’ cells produce these hormones. These hormones are produced in the lining of the stomach and upper small intestine. When a person is having a meal, it is the gastrin which stimulates the stomach to release gastric acid. Aside from the proteins from the food that are broken down, the gastrin makes it possible for the vitamins to be absorbed by the stomach. Gastrin also serves as a disinfectant and kills most of the bacteria that enter the stomach with food, minimising the risk of infection within the gut. It also stimulates the stomach lining’s growth as well as it also increases muscle contractions of the gut to aid digestion. On the other hand, the gastrointestinal hormones or the gut hormones constitute a group of hormones secreted by enteroendocrine cells in the stomach, pancreas, and small intestine that control various functions of the digestive organs.