Glucuronidation Metabolomic Fingerprinting to Map Host-Microbe Metabolism.

Glucuronidation is an important detoxification pathway that operates in balance with gastrointestinal microbial β-glucuronidase (GUS) enzymes that can regenerate active metabolites from their glucuronidated forms. Although significant progress has been made in characterizing GUS enzymes, methods to comprehensively define the glucuronidome - the collection of glucuronidated metabolites - remain limited. In this study we employed pattern-filtering data science approaches alongside untargeted LC-MS/MS metabolomics to map the glucuronidome in urine, serum, and colon/fecal samples from gnotobiotic and conventional mice. Our findings reveal microbiome-driven shifts in the glucuronidome, highlighting how differential GUS activity can influence host metabolite profiles. Reverse metabolomics of known glucuronidated chemicals and glucuronidation pattern filtering searches in public metabolomics datasets exposed the diversity of glucuronidated metabolites in human and mouse ecosystems. In summary, we present a new glucuronidation fingerprint resource that provides broader access to and analysis of the glucuronidome. By systematically capturing glucuronidation patterns, this resource enhances unknown metabolite annotation efforts and provides new insights into the dynamic relationship between the host and bacterial biotransformation activities.