Do you have any experience with a SIBO breath test that uses dextrose as a substrate? My daughter had one done by Commonwealth Labs, and I wonder if these results could be interpreted the same way as if it had been done using lactulose or glucose.

Dr. Amy Nett: Dextrose is chemically identical to glucose. Dextrose and glucose are effectively the same sugar, so if you have a SIBO breath test that lists dextrose as being used as the substrate, that is the same thing as glucose being used as the substrate.