Lactose intolerance and other disaccharidase deficiency

Area of Science:

• Genetics and Molecular Biology
• Gastroenterology
• Nutrition Science

Background:

• Lactose intolerance arises from lactase deficiency, genetically determined by the LCT gene on chromosome 2q21.
• Symptoms can be triggered by "hidden" lactose in inadequately labeled processed foods, complicating diagnosis.
• Distinguishing lactose intolerance from milk allergy is crucial due to overlapping symptoms.

Purpose of the Study:

• To review the types, symptoms, and management strategies for lactose intolerance.
• To emphasize the challenges posed by "hidden" lactose in processed foods.
• To clarify the differences between lactose intolerance and milk allergy.

Main Methods:

• Review of existing literature on lactose intolerance, LCT gene, and related polymorphisms.
• Analysis of diagnostic challenges, including "hidden" lactose and differential diagnosis with milk allergy.
• Discussion of dietary management and patient counseling.

Main Results:

• Lactase deficiency, linked to LCT gene polymorphisms (C/T13910, G/A22018), causes lactose intolerance symptoms.
• Inadequately labeled processed foods (meats, bread, drinks) often contain "hidden" lactose.
• Breath hydrogen tests correlate with hypolactasia and symptoms.

Conclusions:

• Dietary removal of lactose is the primary management strategy for lactose intolerance.
• Awareness of "hidden" lactose in processed foods is essential for patients.
• Accurate diagnosis differentiating from milk allergy improves patient outcomes.