A Probe-Enabled Approach for the Selective Isolation and Characterization of Functionally Active Subpopulations in the Gut Microbiome.

Commensal microorganisms in the mammalian gut play important roles in host health and physiology, but a central challenge remains in achieving a de-tailed mechanistic understanding of specific microbial contributions to host biochemistry. New function-based approaches are needed that analyze gut microbial function at the molecular level by coupling detection and measurements of in situ bio-chemical activity with identification of the responsible microbes and enzymes. We have developed a platform employing β-glucuronidase selective activity-based probes to detect, isolate, and identify the microbial subpopulations in the gut responsible for this xenobiotic metabolism. We find that metabolic activity of gut microbiota can be plastic and that between individuals and during perturbation, phylogenetically disparate populations can provide β-glucuronidase activity. Our work links biochemical activity with molecular-scale resolution without relying on genomic inference.