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

DCA exposure promotes a metabolic interaction between Escherichia coli and Clostridioides difficile that enhances CDI severity through proline cross-feeding.

• Why it matters: Understanding why some patients experience CDI recurrence despite metabolic recovery remains unclear, highlighting the need to explore microbial interactions under DCA influence.
• What they did: The study used in vitro co-culture and murine infection models to show that DCA stimulates EC to produce L-proline, which is then utilized by CD via D-proline reductase, with additional experiments confirming the essential role of this interaction.
• The result: This mechanism suggests that DCA-driven proline cross-feeding between EC and CD contributes to CDI exacerbation and recurrence, providing insight into microbial metabolic pathways involved in disease severity.