The clinical value of breath hydrogen testing

Area of Science:

• Gastroenterology
• Diagnostic Medicine

Background:

• Breath hydrogen testing is used to assess carbohydrate malabsorption and guide low fermentable carbohydrate (FODMAP) diets.
• It's also applied for detecting small intestinal bacterial overgrowth (SIBO).

Purpose of the Study:

• To review the evidence on the clinical utility of breath hydrogen testing in functional bowel disorders.
• To assess limitations in methodology, interpretation, reproducibility, and correlation with symptoms.

Main Methods:

• A review of existing studies examining breath hydrogen test methodology and interpretation.
• Analysis of factors affecting test accuracy, reproducibility, and clinical relevance.

Main Results:

• Significant heterogeneity exists in testing parameters, response definitions, and carbohydrate doses used.
• Poor intra-individual reproducibility was noted for fructose and lactulose breath tests.
• Symptom induction during testing poorly correlates with malabsorption, and SIBO diagnosis via lactulose breath test is unreliable.

Conclusions:

• Methodological limitations and poor reproducibility question the clinical value of breath hydrogen tests.
• Current evidence suggests limited utility in guiding clinical decisions for functional bowel disorder patients.