A real-world study of 1,984 adults using an app-connected breath analyzer found that just one week of low-FODMAP eating significantly lowered breath hydrogen and methane and reduced bloating, abdominal pain, and flatulence, with the biggest absolute gains in those starting with moderate/severe symptoms—hinting that simple, nonfasting breath-gas tracking could personalize who benefits most from FODMAP restriction.
- Breath hydrogen closely mirrored mealtimes and symptom peaks; both H₂/CH₄ and symptoms fell during the low-FODMAP week (all P < 0.0001).
- Baseline H₂/CH₄ were higher in patients with worse symptoms; hydrogen reductions correlated with symptom improvement more than methane.
- Observational, app-guided design without a control group limits causality, but supports breath gases as a practical biomarker to guide and avoid over-restriction.