GLP-1 Receptor Agonist Use Is Associated With Small Intestinal Bacterial Overgrowth and Intestinal Methanogen Overgrowth

Abstract

Introduction:

Glucagon-like peptide-1 (GLP-1) receptor agonists (GLP1RAs) are increasingly used to treat obesity and other metabolic conditions; however, they are known to inhibit gastrointestinal motility. Since gastrointestinal microbial overgrowth (MO) can arise in states of intestinal stasis, we sought to investigate the potential association between GLP1RA use and MO.

Methods:

We analyzed data from 99 patients prescribed GLP1RAs who subsequently underwent testing for MO via intestinal aspirate culture or glucose or lactulose breath tests.

Results:

Most patients had diabetes. Among patients who underwent culture, 76.2% tested positive for small intestinal bacterial overgrowth (SIBO) at a threshold of ≥10³ CFU/mL, with a significant association found between proton pump inhibitor (PPI) use and SIBO. At ≥10⁵ CFU/mL, 33.3% tested positive for SIBO, and neither PPI use nor surgical history was associated. Breath testing revealed a 30.6% positivity rate for MO, predominantly characterized by intestinal methanogen overgrowth (IMO). There was no association between control of diabetes and positive MO tests.

Conclusion:

GLP1RA use is associated with SIBO, although diabetes may be a confounder.

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