The goal with a SIBO breath test is to identify an overgrowth of microbes in the small intestine, by measuring the production of hydrogen and, or, methane production in response to the sugar solution that is swallowed at the start of the test. The two sugar solutions that are used with SIBO breath testing are glucose and lactulose. Many times I have heard patients voice concern over using a lactulose breath test when they are lactose intolerant. Let me clear this up and share with you some tips for getting the ‘cleanest’ SIBO breath test results.
The two sugar substrates used with these tests are lactulose and glucose. I prefer the lactulose three hour test. Lactulose is a synthetic sugar that is made in the lab. It is not digested or absorbed by human cells and that is why this is used – so it travels the length of the small intestine and makes its way into the colon. It is not lactose. Having a lactose intolerance does not exclude you from taking this test. If you have a lactose allergy, then you should not take this test. True lactose allergies make up a very, very small subset of the population. Again, you can absolutely take this test if you have lactose intolerance. A lactose intolerance will also not effect the test results.
- Lactulose is not lactose.
- Lactulose is a synthetic sugar that is manufactured in the lab.
- It is used because it is not digested and absorbed by human cells.
- A lactose intolerance has nothing to do with whether you should or shouldn’t do a lactulose breath test, nor will it interfere with the test results.
It is pretty fascinating if you think about how this test works. I ingest a sugar solution, and then breathe into a tube at twenty minute increments. The microbes that are in my small intestine ingest the sugar, and release gas as a byproduct. The gas builds up in my small intestine and passes through the lining into my blood stream, which then circulates in my body and the gas is exchanged through my lungs and expelled out into my breath, where we can measure gas production. Gas production is measured in parts per million at baseline (the start of the test) and then in twenty minute increments during the ninety minute or three hour test.
"How to Get Most Accurate SIBO Breath Test Post SIBO Guru"↑ Tweet This
A test is positive if there is a greater than 15 ppm (parts per million) rise in hydrogen over baseline, a greater than 3 ppm rise in methane over baseline, or a combination of hydrogen and methane rise of greater than 12 ppm over baseline.
What we are also looking for is a double peak of hydrogen and, or, methane – once when the sugar substrate hits SIBO microbes in the small intestine (often by the 90-120 minute mark) and a second when it enters the colon and the large numbers of microbes in the colon consume the sugar substrate and produce gas.
When I review SIBO breath tests, a good majority of these have a high baseline of or methane. This still may be considered a positive test, if the patient has been fully compliant with the test prep instructions. But, what we would rather see is a very minimal gas production at baseline to then compare the rise in hydrogen and methane as the sugar substrate moves along the small intestine.
I also prefer Quintron and CommonWealth Labs for this test, since they also measure CO2 levels with each vial. This measure tells us whether the test interval was collected correctly or not.
Obviously everybody wants to have their test results be as accurate as possible. The test prep instructions are meant to greatly reduce the fermentable load from supplements, medications, food and drink, and to minimize any exposures, like poor oral health hygiene, that will skew the test results. This also means trying to minimize gas production at baseline.
My post today offers some suggestions to minimize a high baseline reading on your SIBO breath test. Let’s first talk about what you will be doing to prep for the test.
When prepping for the test (whether you are using the SIBO Breath test with glucose or lactulose as the sugar substrate) it is imperative that you follow the patient preparation guidelines that are offered by the test provider.
These instructions often include:
1. No smoking, or being around second hand smoke, the day of the test.
2. That you brush your teeth prior to the test and use good oral hygiene practices (this reduces the number of microbes in your mouth that may compromise the test results)
3. No sleeping an hour prior to the test or vigorous exercise the day of the test.
4. That you wait 14 days post antibiotic treatment, a barium study, use of an enema or colonoscopy and that you wait at least 7 days post PPI – or, proton pump inhibitor use, prior to starting the breath test.
The day prior to the test you will be instructed to prep for the test by limiting your diet to only a few ‘prescribed’ LOW fermentable foods, these often include chicken, fish or turkey, white bread, white rice, eggs and clear broth.
If you are offered further advice on the preparation of your test, please adhere fully to these instructions.
Here are a few additional suggestions to prepare for your test:
1. If you consume clear broth, make sure that this was not prepared with fermentable vegetables like garlic, onion, mushrooms or celery. Even though this is a clear broth and you are not consuming the actual vegetable, the fermentable compounds in these vegetables are water soluble. These will leach out into the liquid and likely cause a symptom reaction and they may skew the test results.
2. Use a brand new tooth brush the morning of the test
3. Use a mouthwash with a 3% hydrogen peroxide solution, mixed with equal parts water and swish for two minutes prior to starting the test (Do this prior to starting the test; do not repeat during the test).
4. At the time of the test, if you are experiencing constipation (meaning that you’ve gone multiple days without having a bowel movement) consider doing the food test prep for two days to further reduce the fecal matter that is in your colon, which will reduce colonic fermentation (which can also skew test results)
Lactulose is considered a controlled substance and is only available through a prescription. If you are having a hard time getting a three hour lactulose breath test, I recommend visiting CommonWealth Labs website http://hydrogenbreathtesting.com/. Your doctor does not need to have an account with this lab. All they need to do is to fax the requisition to CommonWealth. CommonWealth mails the kit to your doctor. You would pick the kit up, perform this test at home and then send the test kit in with your payment. I recommend that you fill out the requisition and give this to your doctor. All they will need to do is to sign it and fax it.
Angela Pifer | Functional Medicine Nutritionist
Enjoying this content? Sign up for updates... It's FREE!