Testing For SIBO (Small Intestinal Bacterial Overgrowth)





If you read my last blog post, Is SIBO or SIFO (Small Intestinal Bacterial/Fungal Overgrowth) Causing Your IBS? and this resonated with you, keep reading. This blog post is all about how to test for SIBO, using the Lactulose Breath Test.


We know that SIBO is massively underdiagnosed and could be responsible for up to 85% of IBS cases. But why is SIBO so commonly missed or overlooked?

A big part of the problem is lack of knowledge and testing availability for SIBO in the medical community.

Many people assume they need to go to their doctor for this test, only to find out their doctor is unfamiliar with it. In many countries, you can actually order this test straight from the internet, as it's an 'at-home' test. Although I definitely encourage you to work with someone who has experience in interpreting lactulose breath test results and providing the appropriate treatment protocol, my point is, this doesn't necessarily need to be a medical doctor.


In this blog post, we will cover:


- The lactulose breath test

- Limitations of the test

- Do you have to test?

- Hydrogen Sulfide SIBO

- What about stool tests?



The Lactulose Breath Test


The ‘gold standard’ for non-invasive SIBO testing is a breath test that measures the levels of hydrogen and methane gas in your breath. I use the SIBO Lactulose Test with my clients, which is a simple, non-invasive test that can be ordered online and completed at home.

After a 1-2 day prep diet, a baseline breath sample is taken before a lactulose solution is swallowed and breath samples are collected every 15-20 minutes for 2.5 to 3 hours (depending on the lab used), so 10 samples in total. If bacteria are present, they will ferment the lactulose and produce hydrogen and/or methane gas, which we can then measure through your breath.

In simple terms, if the gas levels are above a certain number within a certain time period, then the test indicates a positive result for SIBO. Using the correct solution and interpretation of results is a science all and of itself. Having a practitioner, skilled in the interpretation of SIBO breath tests is key to getting the right diagnosis. See below for a sample of what test results look like.




Interpreting the results