Deoxycholate induces proline provision from Escherichia coli to enhance Clostridioides difficile virulence.

Deoxycholate promotes Clostridioides difficile virulence by stimulating Escherichia coli to produce proline, boosting infection severity by 50-fold in co-infection models.

• Why it matters: Understanding why CDI recurs despite metabolic recovery is crucial, as current treatments often fail to prevent relapse, highlighting gaps in knowledge about microbial interactions in the gut.
• What they did: The study combined in vitro co-culture experiments and murine infection models to investigate how DCA influences EC and CD interactions, focusing on amino acid exchange and biofilm formation.
• The result: Findings reveal EC produces L-proline in response to DCA, which is utilized by CD to enhance its pathogenicity, offering insights into metabolic cross-feeding that exacerbate CDI and potential therapeutic targets.