Why Calories Are Not the Same - a Gut Explanation?

The aim of this study is to understand how the gut microbiome influences how much dietary energy humans excrete via feces. This study is based on the hypothesis that levels of methane in exhaled breath represent two different gut microbiome community structures, and therefore influence fecal energy excretion differently. Moreover, this study is assessed in the context of two different diets, both isocaloric and equal in macronutrient composition, but differing in contents of fiber, resistant starch, and large particles; which are hypothesized to impact the gut microbiome differently.

NCT Number	NCT06932666
Lead Sponsor	University of Copenhagen Collaborators: Wageningen University and Research
Conditions	Diet, Healthy, Breath Analysis
Enrollment	60 participants
Start Date	2025-05-15
Primary Completion	2026-05-13 (estimated)
Study Completion	2026-05-13 (estimated)
Updated on ClinicalTrials.gov	2026-06-02