Alactasia

Alactasia

Alactasia is a rare metabolic disorder characterized by the absence or deficiency of the enzyme lactase, which is responsible for the digestion of lactose, a sugar found in milk and dairy products. This condition leads to the inability to properly digest lactose, resulting in gastrointestinal symptoms when dairy products are consumed.

Pathophysiology

Lactase is an enzyme produced in the small intestine, specifically by the enterocytes lining the intestinal villi. Its primary function is to hydrolyze lactose into glucose and galactose, which can then be absorbed into the bloodstream. In individuals with alactasia, the production of lactase is either absent or significantly reduced, leading to the accumulation of lactose in the gut.

The undigested lactose is fermented by bacteria in the colon, producing gases such as hydrogen, methane, and carbon dioxide, as well as short-chain fatty acids. This fermentation process results in symptoms such as bloating, flatulence, abdominal pain, and diarrhea.

Clinical Presentation

Patients with alactasia typically present with symptoms following the ingestion of lactose-containing foods. Common symptoms include:

• Abdominal pain and cramping
• Bloating
• Flatulence
• Diarrhea
• Nausea

The severity of symptoms can vary depending on the amount of lactose consumed and the degree of lactase deficiency.

Diagnosis

The diagnosis of alactasia can be confirmed through several methods:

• Lactose Tolerance Test: This involves the oral administration of a lactose solution followed by measurement of blood glucose levels. A lack of increase in blood glucose suggests lactase deficiency.

• Hydrogen Breath Test: This test measures the amount of hydrogen in the breath after the ingestion of lactose. Increased levels of hydrogen indicate lactose malabsorption.

• Stool Acidity Test: This test is primarily used in infants and young children. The presence of acidic stool suggests lactose fermentation in the colon.

Management

Management of alactasia primarily involves dietary modifications to reduce or eliminate lactose intake. This can include:

• Lactose-Free Diet: Avoidance of milk and dairy products or the use of lactose-free alternatives.

• Lactase Supplements: Over-the-counter lactase enzyme supplements can be taken before consuming lactose-containing foods to aid in digestion.

• Calcium and Vitamin D Supplementation: Since dairy products are a major source of calcium and vitamin D, supplementation may be necessary to prevent deficiencies.

Prognosis

With appropriate dietary management, individuals with alactasia can lead normal, healthy lives. However, it is important to ensure adequate intake of essential nutrients that may be lacking due to dietary restrictions.

Also see

• Lactose intolerance
• Lactase persistence
• Galactosemia
• Enzyme deficiency