Science We Like - Biomarkers
A few published works that show that the gasses mean something.
Last updated: 1/5/2026
Leite et al. (2024): Identifying "Disruptor" Blooms via Gas
This study used high-throughput sequencing to prove that specific gas-producing pathways are the signature of "disruptor" taxa that take over the small bowel.
• Fermentation Pathways: It found that carbohydrate fermentation and -production pathways are significantly enhanced in subjects with SIBO, driven specifically by blooms of two E. coli strains and two Klebsiella species.
• Functional Validation: The study argues that on breath tests is not merely a marker of rapid transit but derives from the small intestine, providing a functional readout of the exaggerated ability of these specific disruptors to ferment substrates
Rezaie et al. (2025): Tracking Ecological Shifts During Intervention
This prospective trial demonstrates that breath gases provide an objective data stream to monitor the success of microbiome-targeted interventions.
• Response Monitoring: After a 2-week Elemental Diet, 73% of subjects normalized their breath tests; this gas reduction directly corresponded to a measurable decrease in the relative abundance of key taxa such as M. smithii and Fusobacterium.
• Shift in Patterns: The study observed a transition from a small bowel fermentation pattern (early rise) to a colonic pattern following treatment, proving that time-series gas data can pinpoint exactly where and how microbial activity is changing
Takakura et al. (2022): Direct Correlation of Gas to Population Load
This study establishes a definitive link between the concentration of exhaled gas and the physical "load" of specific microbes in the gut
Population Marker: It proved that a Single Fasting Methane Measurement (SMM) positively correlates with the fecal load of Methanobrevibacter smithii (R = 0.65, P < 0.0001).
Activity Stability: The research demonstrated that these gas levels remain stable over 14 weeks without treatment but rapidly drop within two days of initiating antibiotic therapy, proving that breath gases are sensitive indicators of real-time population shifts.
Villanueva-Millan et al. (2025): Mapping "Microtypes" and Competition
This paper confirms that breath gases can differentiate between distinct "microtypes" or ecological states of the small bowel.
• Hydrogen Sulfide (H2S) Dynamics: It identified that higher breath H2S levels correlate with the prevalence of specific sulfate-reducing bacteria like Proteus mirabilis and Desulfovibrio.
• Syntrophic Relationships: The research found that methane producers correlate with known hydrogen-producing syntrophs (like Christensenella minuta), proving that breath patterns reflect the inter-species "co-occurrence" and gas-sharing dynamics of the microbiome
