Skip to content
Back to glossary
Microbiome

Microbial beta-glucuronidase

DEMikrobielle Beta-Glucuronidase

Microbial beta-glucuronidases (GUS) are enzymes made by many of your gut bacteria. (They live in the Firmicutes, Bacteroidota, and Enterobacteriaceae.) They snip off glucuronide tags that your own body added during 'phase-II' detox. That regenerates the original compound back in your gut. This has two well-known consequences. First, it can reactivate drugs and toxins. Examples are SN-38 and NSAIDs. SN-38 is the active form of the chemo drug irinotecan. There, this reactivation drives dose-limiting diarrhea. Second, it can free up your steroid hormones, like estrogens. Plottel and Blaser named that set of activities the 'estrobolome'. A 2017 structural atlas (Pollet et al., in Structure) is the key reference. It cataloged 279 unique gut GUS proteins, across six structural classes, from Human Microbiome Project data. That work motivated the search for selective GUS inhibitors, as add-ons to chemotherapy.

Last reviewed:

This definition is educational and is not medical advice, a diagnosis, or treatment. Talk to a doctor about any health decisions. Read our full medical disclaimer

Sources

  1. Pollet RM, D'Agostino EH, Walton WG, et al.. (2017). An atlas of beta-glucuronidases in the human intestinal microbiome. *Structure*doi:10.1016/j.str.2017.05.003
  2. Plottel CS, Blaser MJ. (2011). Microbiome and malignancy. *Cell Host & Microbe*doi:10.1016/j.chom.2011.10.003
  3. Hu S, Ding Q, Zhang W, et al.. (2023). Gut microbial beta-glucuronidase: a vital regulator in female estrogen metabolism. *Gut Microbes*doi:10.1080/19490976.2023.2236749