Question

Explain lactose intolerance.

Answer 1

Hint: Lactose intolerance is the inability of the body to accept lactose in terms of consumption and digestion. This may occur due to the lack of certain factors that are required for the correct metabolism for lactose.

Complete step by step answer:
- People who have lactose intolerance cannot digest lactose that is present in milk and milk products. When they consume any dairy products, they suffer from bloating, gas, and diarrhea.
- Lactose is a disaccharide composed of two monosaccharides glucose and galactose that are bonded by 1,4-glycosidic bonds. It is also known as milk sugar as it is found in the milk of all mammals. Compared to other sugars, it is tasteless.
- The intolerance occurs due to the lack of the enzyme lactase that is present in the intestinal brush border of the small intestine. Lactase breaks down lactose to form glucose and galactose that get absorbed in the intestinal lining and get assimilated in the blood.
- Diseases that occur that have similar symptoms and causes as lactose intolerance are celiac diseases, irritable bowel syndrome, and milk allergies.
- Risk factors that may develop lactose intolerance include aging, ethnicity, premature birth, diseases of the small intestine, and certain cancer treatments.
- There are four types of lactose intolerance. Primary lactose intolerance occurs from a decline in the lactase enzyme due to aging. Secondary lactose intolerance occurs due to any injury to the small intestine. Developmental lactose intolerance occurs in premature babies and may improve over time. Congenital lactose intolerance is a rare disorder where there is no formation of lactase from birth.
- Treatment includes avoidance and substituting milk products with non-dairy products and lactase supplements.
- Lactose intolerance does not damage the gastrointestinal tract.
- Lactose monohydrate is the crystalline form of lactose present in milk. It is soluble in water and it loses the monohydrate on heating.
- Intestinal diseases occur due to bacterial overgrowth, celiac disease, and Crohn's disease.

Note:
- Other examples of disaccharide sugars are maltose and sucrose.
- Premature babies may suffer from lactose intolerance because the small intestine doesn't develop lactase-producing cells until late in the third trimester.