Hydrogen Production Dynamics During Lactulose Breath Testing in Patients with Suspected SIBO

Area of Science:

• Gastroenterology
• Microbiology
• Diagnostic Medicine

Background:

• Small intestinal bacterial overgrowth (SIBO) involves excessive bacteria in the small intestine.
• Hydrogen breath tests are common for SIBO diagnosis, but focus on thresholds, not hydrogen production dynamics.
• Understanding hydrogen production patterns can refine SIBO diagnostics.

Purpose of the Study:

• To investigate the hydrogen production dynamics during lactulose breath testing in individuals with chronic gastrointestinal symptoms.
• To compare total and phase-specific hydrogen production between SIBO-positive and SIBO-negative individuals.

Main Methods:

• A cross-sectional study of 162 adults with chronic GI symptoms undergoing lactulose hydrogen breath testing.
• Hydrogen concentrations measured every 20 minutes for 180 minutes.
• Total hydrogen production quantified by Area Under the Curve (AUC); early (0-60 min) and late (>60 min) phases analyzed.

Main Results:

• 100 participants (61.7%) were SIBO-positive, 62 (38.3%) were SIBO-negative.
• SIBO-positive individuals showed significantly higher total hydrogen production (mean AUC: 6938 vs. 2292 ppm × min, p < 0.001).
• Markedly elevated hydrogen levels were observed in SIBO-positive individuals during the late phase (52.7 vs. 12.0 ppm, p < 0.001).

Conclusions:

• SIBO is strongly associated with increased hydrogen production during lactulose breath testing, particularly in the late phase.
• Findings enhance understanding of hydrogen production dynamics in breath testing.
• Further research is needed for clinical application; results should be interpreted within existing classification frameworks.