Gastric lipase is a protein that digests fat in the stomach. Together with the protein lingual lipase, gastric lipase accounts for 30 percent of fat digestion in adults and up to 50 percent of fat digestion in infants.
Gastric lipase and lingual lipase are collectively called the acidic lipases. These proteins differ from other fat digestion mechanisms because they do not require the presence of bile to function. This allows some fat digestion to occur in individuals with compromised pancreatic function.
Gastric and lingual lipases both function primarily in the stomach. In patients with cystic fibrosis and pancreatic disorders, these proteins continue to function in the small intestine. This is due to the lack of the alkaline lipases normally present in the small intestine.