Lactose intolerance: how does it work?

Milk and dairy products are an integral part of many cuisines of the world. We drink milk, add it to cereal and granola, use it in baking, make yogurts, ice cream, cheeses and much more from it. However, milk doesn't bring joy for everyone. Some people can't digest dairy products due to lactose intolerance.

Lactose intolerance is a consequence of a deficiency of lactase, an enzyme responsible for the breakdown of lactose.

Lactose is a carbohydrate of the disaccharide group. As a disaccharide, it can't be directly absorbed through the wall of the small intestine into the blood, and in the absence of lactase, the molecules of this sugar pass without enzymatic cleavage into the large intestine. Bacteria in the colon can process lactose by producing a mixture of gases such as hydrogen, carbon dioxide and methane as a result, which leads to various intestinal disorders.

There are several nutritional options for people with lactose intolerance: some of them can tolerate products that have undergone lactic acid fermentation, such as cheese and yogurt. Those whose intolerance is too developed can consume special dairy products containing very small amounts of lactose, such as lactose-free milk. In addition, they can take the lactase enzyme in the form of tablets together with dairy products. 

It is interesting that people with lactose intolerance are able to consume ice cream without any complications. The fact is that lactose can be broken down not only by lactase (β-galactosidase) but also by α-glucosidase. Clinical experiments have shown that small additions of sugar to a dairy product significantly increase lactose tolerance. Those with a sweet tooth can enjoy ice cream even if they are lactose intolerant. ;)