| First Author | Aguirre AM | Year | 2021 |
| Journal | PLoS Pathog | Volume | 17 |
| Issue | 10 | Pages | e1010015 |
| PubMed ID | 34665847 | Mgi Jnum | J:313688 |
| Mgi Id | MGI:6787874 | Doi | 10.1371/journal.ppat.1010015 |
| Citation | Aguirre AM, et al. (2021) Bile acid-independent protection against Clostridioides difficile infection. PLoS Pathog 17(10):e1010015 |
| abstractText | Clostridioides difficile infections occur upon ecological / metabolic disruptions to the normal colonic microbiota, commonly due to broad-spectrum antibiotic use. Metabolism of bile acids through a 7alpha-dehydroxylation pathway found in select members of the healthy microbiota is regarded to be the protective mechanism by which C. difficile is excluded. These 7alpha-dehydroxylated secondary bile acids are highly toxic to C. difficile vegetative growth, and antibiotic treatment abolishes the bacteria that perform this metabolism. However, the data that supports the hypothesis that secondary bile acids protect against C. difficile infection is supported only by in vitro data and correlative studies. Here we show that bacteria that 7alpha-dehydroxylate primary bile acids protect against C. difficile infection in a bile acid-independent manner. We monoassociated germ-free, wildtype or Cyp8b1-/- (cholic acid-deficient) mutant mice and infected them with C. difficile spores. We show that 7alpha-dehydroxylation (i.e., secondary bile acid generation) is dispensable for protection against C. difficile infection and provide evidence that Stickland metabolism by these organisms consumes nutrients essential for C. difficile growth. Our findings indicate secondary bile acid production by the microbiome is a useful biomarker for a C. difficile-resistant environment but the microbiome protects against C. difficile infection in bile acid-independent mechanisms. |
