Reduction of Methane Levels Correlates with Fecal Abundance of M. smithii

Presented at DDW 2025 | Watch Video

Overview
Breath methane is a marker of methanogenic activity in the gut, primarily driven by the archaeon Methanobrevibacter smithii. High breath methane is associated with symptoms such as constipation and bloating in intestinal methanogen overgrowth (IMO). This study enrolled participants who completed a two-week exclusive oral elemental diet (mBIOTA), with breath methane measured before and after the intervention. Additionally, fecal samples were analyzed to quantify the abundance of M. smithii and explore relationships between microbiota changes and methane production. 

Results
After two weeks of mBIOTA Elemental, participants showed a significant reduction in breath methane levels compared with baseline. This decrease correlated with a reduction in the fecal abundance of Methanobrevibacter smithii. Fecal abundance reflects the contents of the gut microbiome. The findings suggest that the mBIOTA Elemental Diet altered the gut environment in a way that reduced the activity and abundance of these methane-producing organisms. Some participants also experienced symptom improvement, particularly those who started with higher methane levels.

Conclusion
A 2-week course of the mBIOTA Elemental Diet substantially reduced breath methane production in study participants, with these reductions closely linked to decreases in Methanobrevibacter smithii abundance in fecal samples. These findings support that mBIOTA can modulate methanogenic gut microbe populations and their gas output.