This is important because “SIBO” has become a really popular “internet diagnosis”, and the primary intervention is an antibiotic with potentially severe side effects.

Key points

• The SIBO-IBS hypothesis has stimulated significant research into the role of the microbiota in symptoms of DBGI but remains unproven.
• This hypothesis has resulted in serious unintended consequences, namely the use of poorly validated breath tests to diagnose SIBO and the resulting injudicious use of antibiotics.
• The lactulose breath test (LBT) is primarily a measure of intestinal transit and has very low sensitivity and specificity to diagnose SIBO.
• The glucose breath test (GBT) has better performance characteristics if the pre-test probability is high, as found in conditions underlying classical SIBO, but also has a high false-positive rate in DGBI.
• Future studies in DGBI are needed to better understand the impact of bacterial communities, their metabolites, and diet-host interactions in the small and large intestine on DGBI symptoms and move away from the sole focus on absolute numbers of bacteria.

In this review, we examine why the SIBO hypothesis remains unproven and, given the unintended consequences, discuss why it is time to reject this hypothesis and its reliance on breath testing.

More info & discussion.