How does lactase deficiency affect digestion?

Lactase deficiency affects digestion by causing difficulty in breaking down lactose, a sugar found in milk and dairy products.

Lactase is an enzyme produced in the small intestine that plays a crucial role in the digestion of lactose. Lactose is a disaccharide sugar found in milk and dairy products, which needs to be broken down into simpler sugars, glucose and galactose, for absorption into the bloodstream. When there is a deficiency of lactase, the body struggles to digest lactose, leading to digestive problems.

Lactase deficiency can be congenital or acquired. Congenital lactase deficiency is a rare genetic disorder where the small intestine produces little to no lactase from birth. Acquired lactase deficiency, also known as lactose intolerance, is more common and usually develops over time as the amount of lactase produced by the body decreases. This can occur due to ageing, or as a result of damage to the small intestine from diseases like celiac disease or Crohn's disease.

When lactose is not properly digested due to lactase deficiency, it moves into the large intestine without being processed. Here, it is fermented by the bacteria in the colon, producing gases such as hydrogen, carbon dioxide and methane. This can lead to symptoms such as bloating, diarrhoea, abdominal cramps, and flatulence. These symptoms usually occur within a few hours of consuming lactose-containing foods or drinks.

In addition to these uncomfortable symptoms, lactase deficiency can also affect the absorption of other nutrients. For instance, undigested lactose can draw water into the intestine, which can result in diarrhoea and potentially lead to dehydration and loss of other nutrients. Furthermore, the fermentation of lactose in the colon can lower the pH of the colon, potentially affecting the absorption of other nutrients and minerals.

In conclusion, lactase deficiency significantly impacts digestion by hindering the breakdown and absorption of lactose, leading to a range of digestive symptoms and potentially affecting the absorption of other nutrients. It's a condition that requires dietary management to avoid discomfort and potential nutritional deficiencies.