A hormone synthesized by the cells of the stomach and small intestine, gastrin plays an important role in the digestion process.
Gastrin actually boosts the production of hydrochloric acid, an acid which begins to digest proteins. The main problem that can affect gastrin production is the formation of a tumor in the cells synthesizing this hormone. This increases gastrin production well above normal. This is followed by the appearance of Zollinger-Ellison syndrome (numerous ulcers in the digestive system and fatty diarrhea).