Interpretation of SIBO Results
We have defined a positive SIBO result according to the kit and instrument manufacturer’s recommendations and the criteria most widely supported by clinical research.
A positive SIBO result is one that satisfies any one of the following criteria:
- A rise in hydrogen ≥ 20 ppm above the lowest preceding time point measured within the first 100 minutes.
- A rise in methane ≥ 12 ppm above the lowest preceding time point measured within the first 100 minutes.
- A combined rise in hydrogen and methane ≥ 15 ppm above the lowest preceding time point measured within the first 100 minutes.
While a high baseline measurement (≥20 ppm hydrogen or ≥12 ppm methane) is not reported as a positive result, such a result may indicate the presence of SIBO. However, a high baseline followed by a reduction or sustained drop in gas levels is usually an indicator of preparatory diet noncompliance. Additionally, a prolonged transit time, as seen in some cases of constipation, can lead to a delayed elevation in bacterial gases, which may appear after 100 minutes. It is ultimately up to the provider to weigh both the clinical evidence and the SIBO test results to determine if treatment for SIBO is warranted.