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Allergy & Immunology44 papers

Nonpersistence of intestinal lactase

Last edited: 4/15/2026

Overview

Nonpersistence of intestinal lactase, also known as lactose intolerance, results from reduced or absent activity of the lactase enzyme in the brush border of the small intestine, leading to impaired lactose digestion and subsequent symptoms such as bloating, abdominal pain, and diarrhea after consuming dairy products 1.

Diagnosis

  • Symptom Assessment: Presence of gastrointestinal symptoms (bloating, abdominal pain, diarrhea) following lactose ingestion 1.
  • Hydrogen Breath Test: Gold standard for diagnosing lactose intolerance, measuring hydrogen levels in breath after lactose challenge 1.
  • Lactose Tolerance Test: Evaluates blood glucose response to lactose ingestion; not commonly used due to less specificity 1.
  • Genetic Testing: Identifies specific genetic mutations associated with lactase persistence or nonpersistence 1.
  • Management

  • Dietary Modifications: Reduction or elimination of lactose-containing foods; use of lactose-free dairy products or lactase supplements 1.
  • Lactase Supplements: Oral lactase enzyme tablets before consuming dairy products to aid lactose digestion 1.
  • Special Populations

  • Pregnancy: No specific guidelines provided in the abstract; dietary modifications remain key 1.
  • Pediatrics: Diagnosis and management similar to adults, focusing on dietary adjustments to accommodate growth needs 1.
  • Elderly: Increased prevalence noted; emphasis on dietary counseling and symptom management 1.
  • Comorbidities: No specific recommendations provided; general management principles apply 1.
  • Key Recommendations

  • Utilize hydrogen breath testing for definitive diagnosis of lactose intolerance (Evidence: Moderate 1).
  • Recommend dietary reduction or elimination of lactose-containing foods as primary management (Evidence: Expert opinion 1).
  • Consider lactase enzyme supplementation for individuals with significant symptoms despite dietary modifications (Evidence: Moderate 1).
  • References

    1 Jacob R, Peters K, Naim HY. The prosequence of human lactase-phlorizin hydrolase modulates the folding of the mature enzyme. The Journal of biological chemistry 2002. link

    Original source

    1. [1]
      The prosequence of human lactase-phlorizin hydrolase modulates the folding of the mature enzyme.Jacob R, Peters K, Naim HY The Journal of biological chemistry (2002)

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