Q: How common are SIBO test results that are all zeros?
A: Very common. Up to 5% of all Small Intestinal Bacterial Overgrowth tests are all zeros.
Q: Can I take a SIBO test while pregnant?
A: Yes, but you should wait until you are not pregnant to perform the test. The test itself is safe, but no medication can be given if the result is positive.
Q: Which substrate should I use: glucose or lactulose?
- A1: Glucose is a more specific substrate due to the fact that no human should be fermenting this substrate.
- A2: Lactulose gives a more complete picture of the intestinal tract, but it also has a higher rate for false positives.
Q: What is the sensitivity/specificity of your SIBO test?
A: Since there is no gold standard for Small Intestinal Bacterial Overgrowth testing, there is no way to calculate this value; however, patients with Irritable Bowel Syndrome have abnormal breath test results compared to healthy patients by a factor of 10.
Q: What is the difference between the substrates glucose and lactulose?
A: Lactulose is a synthetic disaccharide that cannot be digested or absorbed by human cells. Many providers use lactulose when administering the breath test for Small Intestinal Bacterial Overgrowth as they feel it gives a complete profile of the small intestine and can identify distal overgrowth. Glucose is a simple monosaccharide. Some providers feel that the glucose substrate can be restrictive when doing a breath test for SIBO as it is absorbed very quickly and may only be able to identify overgrowth in the proximal region of the small intestine.