H2S SIBO

Hydrogen Sulfide SIBO: The Third Gas That Standard Tests Missed for Decades

Hydrogen sulfide SIBO is produced by sulfate-reducing bacteria and was undetectable on older two-gas breath tests. The Trio-Smart test now measures all three gases.

Last updated 2026-04-27

Current Consensus

  • Sulfate-reducing bacteria produce hydrogen sulfide gas, invisible on older two-gas breath tests.
  • The Trio-Smart breath test is the first breath test that measures all three gases including hydrogen sulfide.
  • H2S SIBO shows a flat-line pattern on standard tests where hydrogen stays near zero throughout.
  • Hydrogen sulfide is neurotoxic and may explain disproportionate brain fog and fatigue in H2S SIBO.

Open Questions

  • The optimal antimicrobial protocol specifically targeting sulfate-reducing bacteria.
  • The dietary sulfur threshold that triggers symptoms in H2S SIBO patients.

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Medical Disclaimer: The content in this section is for informational and educational purposes only. It does not constitute medical advice, diagnosis, or treatment. Always consult with a qualified healthcare professional before making changes to your health regimen. GLP1Gut is a tracking tool, not a medical device.