Hydrogen Increase Over Baseline by 90 Minutes – SIBO Breath Test Marker
The "Hydrogen increase over baseline by 90 minutes" is a critical marker designed to detect abnormal fermentation in the small intestine. During this test, patients ingest a sugar substrate (typically lactulose), and breath samples are collected over a 2-hour period to measure hydrogen and methane gas levels produced by bacteria.
In a healthy digestive tract, minimal hydrogen is produced in the small intestine, as most bacteria reside in the large intestine. However, a rise in hydrogen of ≥20 parts per million (ppm) above baseline within 90 minutes strongly suggests the presence of SIBO, where excess bacteria ferment carbohydrates prematurely in the small intestine—leading to symptoms like:
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Bloating
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Abdominal discomfort
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Excessive gas
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Diarrhea or loose stools
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Nutrient malabsorption
This marker helps differentiate hydrogen-dominant SIBO from other digestive disorders and guides targeted treatment using antimicrobial herbs, antibiotics, or dietary strategies like the low FODMAP diet.
Why It Matters
An early hydrogen rise is a hallmark of bacterial overgrowth in the small intestine, not the colon. Identifying this pattern allows clinicians to address the root cause of chronic digestive symptoms, reduce inflammation, restore gut balance, and improve long-term gastrointestinal health.
Peak Hydrogen (H2) Production
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