Tests that Can Determine if SIBO is Present
The small intestine is a challenging organ to get to. It is located right in the middle of the body, making it nearly inaccessible without surgery. There are 3 tests that are used to determine the presence of SIBO:
The Lactulose Breath Test
This is the test that I, and many other practitioners choose to use when investigating the presence of SIBO.
I use the Lactulose Breath Test over the Glucose Breath Test, because lactulose is not absorbed into our bloodstream. Instead, lactulose moves through the whole small intestine, into the large intestine. Therefore, the LBT can provide us with a picture of what is going on throughout the entire length of the small intestine. Conversely, glucose is absorbed within the first 3 feet of the small intestine. Therefore the GBT only offers us a peek into the initial few feet of the small intestine, not the whole length of this long organ.
How does the LBT work?
The Lactulose Breath Test is pretty ingenious. Lactulose is food for bacteria, but not humans. After drinking the lactulose, it makes it's through the whole length of our small intestine, feeding the bacteria all along the way. These happily fed bacteria produce different gases when they "eat" the lactulose - Hydrogen, Methane or Hydrogen Sulfide. The gases released from these bugs diffuse into our bloodstream, which travels to our lungs. Once the gas reaches the lungs, it is exhaled along with our breath. A person taking a Lactulose Breath Test breathes into a little tube every 20 minutes. These breath-filled tubes are then sent away to a lab for testing. Humans don't produce Hydrogen or Methane, and generate only very little Hydrogen Sulfide. Therefore, if these gases are present in our breath, it means there is an overgrowth of microbes in our small intestine.
Here are a few lactulose breath test samples:
What to watch out for with a LBT:
If you get a Lactulose Breath Test, make sure that the test runs for three hours. Some only run for two hours. Also, make sure the test is done with a machine that tests for both Hydrogen and Methane. Some machines test for only Hydrogen.
I am lactose intolerant, can I still do the LBT?
Yes, lactose is different than lactulose. Some people with severe SIBO may experience worsening of gut symptoms from the lactulose, but this is because of the overgrowth of bacteria eating a tasty meal, not a lactose intolerance.
Tests that Cannot Reveal the Presence of SIBO
There are a few tests that are thought to have the ability to reveal the presence of SIBO, but they cannot. Although very useful, they are not appropriate in identifying SIBO. The tests are:
I would like to hear from you!
Have you been tested for SIBO? Did you do a Lactulose Breath Test?
Lindsay Rusk, R.Ac., fmp
Lindsay Is a Registered Acupuncturist, Functional Medicine Practitioner, Health Investigator, Paleo Enthusiast, and Blogger.
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