How do I take a small intestinal bacterial overgrowth (SIBO) test?

Taking a SIBO test can feel a bit overwhelming, but don't worry, we’re here to help.

Let’s break down what you have to do before the test, and what happens on the test day itself.

First, think about when you’re going to take it: you may need to wait until a few days or weeks after you’ve stopped taking particular supplements or medications.

Then, you need to follow a special diet the day before you take it.

On the day itself, you need to open your kit, get set up, and breathe into the tubes before sending them all off in the post. 

Preparing for the test

  • 4 weeks before the test: finish taking any antibiotics. You should never stop a course of antibiotics in order to take a test: talk to your GP first.
  • 1 week before the test: stop any promotility drugs or supplements (anything that speeds up the passage of food through your gut) and laxatives. Again, you must never stop taking drugs without first consulting your doctor.
  • 1 day before the test: There is a specific diet to follow, plus you should avoid all complex carbohydrates and fermentable foods as they can interfere with the test results. Read our full instructions here.
  • 12 hours before the test: fast and drink only water. Most people find it easy to do a SIBO breath test first thing in the morning, so they can fast overnight.
  • On the day of the test: avoid smoking and physical activity before and during the three-hour test period.

Taking the test

free-post-01 Our test kit will be delivered straight to your door.
calendar-01 Choose a day to take the test: most people find it easiest to do it on a weekend, as they can set aside Saturday to do the diet and then Sunday morning to do the test.

If you have any questions or issues with taking your sample according to the instructions provided, it is important you contact us before you send your sample to the lab. Healthpath cannot guarantee to intercept your sample once it arrives at the lab, so it may still be processed.

solution-01-1 To take the test, first give a baseline breath sample using the kit provided. Then drink the sugary solution, and wait 20 minutes.

After 30 minutes, give another breath sample in a second tube. Repeat this process at the timed intervals specified in the full instructions for a total of 2.5 hours. Read our full instructions here.


You’ll end up with 7 breath-filled tubes in total, which you can then send off to the lab for interpretation.


Return your samples using the pre-paid returns envelope via post box (choose a priority post box where available).


Your sample will be sent to our partner in London (please note the tracking number) then sent to our lab in Germany.


You'll receive an update when it arrives in Germany 2- 5 working days after posting.

What happens next?

Following a SIBO test, you can resume your normal diet while you wait for the results.

You should get your results back within ten working days. 
This will include: 

  • Easy-to-read report, turning complex lab results into meaningful insights and action 
  • Expert advice, our experienced practitioners review your symptoms and test results
  • Personal health plan, a supplement plan based on your results, plus meal plans to support your gut health.