Foundations
What Is SIBO
Small Intestinal Bacterial Overgrowth is not a mystery. It is a measurable, treatable condition — and understanding it is the first act of recovery.
01
The definition
- Excessive bacteria colonising the small intestine, where relatively few should normally live
- Bacteria ferment carbohydrates before the body can absorb them
- Produces hydrogen, methane, and hydrogen sulfide gases
- Diagnosed by breath testing or, less commonly, small-bowel aspirate
02
Three subtypes
- Hydrogen-dominant SIBO — often diarrhoea, rapid transit
- Methane-dominant (IMO) — constipation, slowed motility
- Hydrogen sulfide SIBO — the most recently characterised, sulfurous symptoms
03
Root causes
- Impaired small-intestinal motility (often post-food-poisoning)
- Structural abnormalities — adhesions, diverticula
- Low stomach acid (long-term PPI use)
- Slowed digestion — hypothyroidism, diabetes
- Chronic stress and vagal-nerve changes
04
Why it matters
- SIBO is not rare — it is under-diagnosed
- 60–80% of IBS diagnoses test positive for SIBO
- Treatable with a considered protocol
- Left untreated: nutrient deficiencies, ongoing symptoms, quiet frustration
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