Methane Trajectory Phenotypes on Glucose Breath Testing Are Associated With Slow Colonic Transit: A Group-Based...

Area of Science:

• Gastroenterology
• Microbiology
• Physiology

Background:

• Intestinal methanogen overgrowth (IMO) is defined by a methane (CH4) threshold of ≥10 ppm and linked to slow transit constipation.
• Current diagnostic criteria for IMO may not fully capture the complexity of methane production in constipation.

Purpose of the Study:

• To identify distinct breath methane (CH4) trajectory phenotypes in patients with constipation.
• To assess the association between these phenotypes and slow colonic transit.

Main Methods:

• Retrospective analysis of 188 adults with constipation undergoing glucose breath testing and colonic transit assessment.
• Group-based trajectory modeling to classify CH4 kinetics into phenotypes.
• Comparison of slow transit prevalence and diagnostic performance across identified phenotypes.

Main Results:

• Three distinct CH4 phenotypes were identified: High-Producer (15.4%), Low-Producer (12.8%), and Non-Producer (71.8%).
• The High-Producer phenotype exhibited a rapid and sustained rise in CH4 levels.
• Prevalence of slow colonic transit was significantly higher in the High-Producer phenotype (69.0%) compared to Low-Producer (41.7%) and Non-Producer (28.9%) phenotypes (p<0.001).
• The High-Producer phenotype was independently associated with slow transit (aOR 5.67) and demonstrated higher specificity (92.4%) and positive predictive value (69.0%) for slow transit compared to the general IMO criteria.

Conclusions:

• Breath methane (CH4) trajectories reveal distinct kinetic patterns in patients with chronic constipation.
• The High-Producer CH4 phenotype is strongly associated with slow colonic transit.
• This High-Producer phenotype offers improved diagnostic specificity for slow colonic transit compared to the standard IMO threshold.