Lactase is an enzyme that breaks down lactose, a disaccharide found in milk, into the monosaccharides glucose and galactose. In humans, lactase is located on the membranes of epithelial cells lining the small intestine. Lactose intolerance is caused by the absence or deficiency of this enzyme in the intestinal system 1. Lactase derived from certain strains of yeast is approved for use as a food enzyme by the U.S. Food and Drug Administration (FDA) 2.



  1. Natural Standard Database. 2009.