What Are the Functions of the Enzyme Lactase?

Lactase is a protein that acts as an enzyme. Enzymes are chemicals that help speed up specific biological processes. Lactase is usually produced by cells in your body, but some people who suffer from lactase deficiency may need to take pills or capsules that contain the enzyme. Understanding the functions of lactase, will help you understand your body better and allow you to determine if you need to add lactase supplements to your diet.


Lactase is primarily a digestive enzyme that is produced by specialized cells that line the lumen of the small intestine, Genetics Home Reference explains. These cells absorb nutrients within your digestive tract. The gene responsible for guiding the production of lactase is called the LCT gene and is located on chromosome 21. Damage to this gene can lead to improper lactase production or function.

Function of Lactase

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Lactase's primary function is to break down a type of sugar called lactose. Lactose is a sugar found in milk and other dairy products. As a large sugar compound, lactose cannot be absorbed naturally by your body. In order to metabolize this form of sugar, your body needs lactase to break down lactose into two smaller particles called glucose and galactose. These smaller sugar molecules are more easily absorbed by the cells in your intestine. Without lactase, lactose remains in your digestive tract and cannot be used by your body.

Lactase Deficiency

Some people are unable to produce enough lactase to meet their bodies' needs. In some cases, the lactase enzyme is totally absent. These patients are said to be suffering from lactase deficiency, or lactose intolerance. According to MedlinePlus, a service of the National Institutes of Health, symptoms of lactase deficiency begin 30 minutes to 2 hours after ingesting milk or a similar dairy product. Symptoms include bloating of the stomach, abdominal cramps, flatulence, nausea and diarrhea. Larger doses of dairy products often cause more severe symptoms. Premature births, bowel surgery, intestinal diseases and intestinal infections are all possible risk factors for developing lactose intolerance.

Lactase Supplements

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Lactase supplements are available to patients who suffer from intolerable lactose intolerance. Typically, these capsules are consumed just before you ingest dairy products. The lactase in the capsule dissolves the sugar contained in the food and this permits your body to absorb the sugar. Always consult a physician prior to adding lactase supplements to your diet.