laktoositaluvus

Laktoositaluvus refers to the body's ability to digest lactose, the sugar found in milk and dairy products. This ability depends on lactase, an enzyme produced by enterocytes in the small intestine. Many adults experience a decline in lactase production with age, a pattern called primary lactase non-persistence, while others maintain higher lactase activity into adulthood, known as lactase persistence or lactose tolerance.

Genetic variation in the regulatory region of the LCT gene influences lactase expression. Variants promoting persistence are common in populations with historic dairy farming, especially in Northern and Western Europe; in other regions, lactase persistence is less common. Consequently, prevalence ranges from high in parts of Europe to relatively low in East Asia, Sub-Saharan Africa, and many indigenous groups.

Primary lactase non-persistence is the most common cause of reduced lactose tolerance. Secondary lactase deficiency can occur after intestinal injury, illness, or certain conditions. Congenital deficiency is rare. Symptoms after lactose ingestion include bloating, gas, abdominal pain, and diarrhea, typically within 30 minutes to a few hours.

Diagnosis relies on clinical history and tests such as the hydrogen breath test or lactose tolerance test; genetic testing can support the assessment. Management includes dietary adjustment: reducing or avoiding lactose-containing foods, using lactose-free products, or taking lactase enzyme supplements. Some people tolerate small amounts of lactose, especially when consumed with meals, and fermented dairy products may be better tolerated than milk.