Schematic representation of the microbiota-associated bile acid screening system. The synthesized alkCA probe was incubated in human stool-derived ex vivo communities (SECs) after probe incubation and enrichment using the ACER resin. Enriched metabolites (CA-LNK derivatives) are analyzed via LC-MS/MS. Target metabolites were further verified by both isolation- and synthesis-based methods and then analyzed for physiological and pathological abundance.
