What is methane positive SIBO?

A methane-positive SIBO result—now clinically referred to as Intestinal Methane Overgrowth (IMO)—occurs when a breath test detects methane gas levels of 10 parts per million (ppm) or higher at any point during the three-hour testing window. Unlike hydrogen-dominant SIBO, which is caused by true bacteria colonizing the small intestine, IMO is driven by methane-producing archaea, most notably Methanobrevibacter smithii. These single-celled organisms feed on the hydrogen gas produced by neighboring bacteria, converting it into methane. Because archaea can reside in both the small and large intestines, this distinction is crucial for directing treatment. To understand the specific antimicrobial and dietary protocols needed for clearance, read our guide on [methane SIBO](/methane-sibo).

Disclaimer: This content is reviewed and fact-checked by Daryl Stubbs, Certified Holistic Nutritional Consultant (C.H.N.C), for educational purposes. It does not constitute medical advice or a doctor-patient relationship.