What Does Lactase Enzyme Do? (Infographic).

Ever wondered why some people can’t drink milk without a tummy ache?

It’s all because of this tiny thing in our body called lactase.

I’m going to tell you all about what it does and why it’s so important for enjoying things like ice cream and cheese.

I am Dr. Farahat, a gastroenterologist and founder of oh-mygut.com.

So, if you’ve ever had trouble with milk or are just curious, stick with me, it’s going to be fun and easy to understand what lactase does.

What is lactase?

Lactase is an enzyme that helps the breakdown of lactose (the primary sugar in milk and dairy). In humans and mammals, lactase is produced by enterocytes (the cells lining the small intestine) (reference).

Lactase is different from lactose. Lactose is a polysaccharide sugar that gives milk its sweetness. Lactase is the enzyme inside your body that breaks down (digests lactose).

Lactase concentration is highest among babies during the breastfeeding period.

In most people, lactase is downregulated and decreases with age (especially after the second year of life). A phenomenon known as (lactase non-persistence) is responsible for the high rates of lactose intolerance in adults.

According to research, Over 65% of people are lactose intolerant because of lactase non-persistence or primary lactase deficiency (reference).

What does lactase do to milk?

When the milk reaches your small intestine, the lactase enzyme breaks down the lactose sugar in milk into glucose and galactose.

The lactose in milk is a more complex sugar that cannot be absorbed by your intestinal absorptive cells. What lactose does is break it down into more simple sugar (glucose and galactose) (reference).

Lactase enzyme is what makes you able to consume milk without problems. Unfortunately, Your body is wired to digest lactose during infancy (breastfeeding age). As you grow older, your body’s lactose tends to decrease.

As you become older, you become less able to handle milk and dairy products due to lactase enzyme deficiency.

What happens if you don’t have enough lactase?

Your body’s lactase enzyme can decrease due to a variety of causes (reference):

• A primary lactase deficiency: a downregulation of lactase enzyme as you grow older. This is the leading cause of lactase deficiency in most people.
• Destruction of your small intestinal cells (enterocytes): the destruction of your intestinal lining cells causes a secondary type of lactase deficiency.
• Congenital lactase deficiency: a hereditary disease that causes abnormal absence or deficiency of lactase enzyme since birth.
• Developmental lactase deficiency: due to the immature intestine in preterm babies. This type often improves as the preterm baby grows.

When the lactase enzyme decreases, your digestive system becomes unable to break down the lactose sugar in milk. Consequently, your intestine won’t be able to absorb the complex lactose in milk.

Depending on the ingested amount, around 75% of lactose passes unchanged from the small intestine to the caecum (the first part of the colon) (reference).

As a result, lactose accumulates in the small intestine and travels to your colon. Inside the colon, lactose is consumed by bacteria producing excessive gas and diarrhea.

Symptoms include:

• Abdominal pain.
• Distension and gas (flatulence).
• Nausea and sometimes vomiting.
• Bloating sensation.
• Diarrhea.
• The symptoms often start 30 minutes to two hours after ingesting lactose-containing food or drink.
• The severity of symptoms depends on the amount you ingest. Minimal amounts of lactose produce no symptoms. However, the more you consume lactose, the more severe the symptoms.
• Symptoms dramatically improve when you restrict lactose from your diet.

In the long term, lactose intolerance may cause nutritional problems due to malabsorption. Commonly, Osteoporosis, weight loss, and generalized malnutrition.

What does a lactase supplement do?

Fortunately, we can produce the lactase enzyme commercially from yeasts and molds (reference).

Lactase enzyme supplements act as a replacement for the deficient natural lactase inside your body.

Biochemically produced lactase can be utilized in many ways:

• First, as a supplement (tablets or drops): used to treat lactose intolerance (reference).
• As a food additive: the lactase enzyme can be added to milk and other lactose-containing products to break down lactose and produce lactose-free products (lactose-free milk and yogurt are prepared by adding lactase enzyme).

However, The external lactase enzyme doesn’t break down all lactose in the diet. So, response to these supplements is variable; Some people experience good symptom relief, and others may have no improvement at all (reference).

The variable response to lactase enzyme supplement may be partially due to combined intolerance to other carbohydrates such as FODMAP intolerance and varying severity of the condition (reference).

Learn More:

• Lactose intolerance 101: Causes, types, and treatments.
• What happens if you ignore lactose intolerance.
• Can Lactose Intolerance Go Away? Yes, and No.