If you're lactose intolerant, you can drink the lactulose solution as it's not lactose.
The process the manufacturer uses to make lactulose removes even trace amounts of lactose from the solution.
However, the lactulose solution is not suitable for those with milk allergies.
Why we use lactulose for the SIBO test
Studies have shown that lactulose produces the most reliable results in SIBO tests, which is why we use it as standard. It is less likely to result in a false-negative result. A double-blind randomised study revealed that 84% of IBS patients exhibited bacterial overgrowth based on lactulose breath testing.
Lactulose also travels through the entire small intestine without being absorbed, where as glucose is quickly absorbed in the first three feet of the small intestine. This means that any bacterial overgrowth further along in the small intestine will be missed. Glucose is also consumed by bacteria.
Should I use glucose instead?
Some practitioners use glucose in addition to lactulose to further confirm a SIBO diagnosis, but we do not feel this is necessary.