Overview
- McMaster researchers published peer‑reviewed results on July 8, 2026 showing bacteriophages that target adherent‑invasive E. coli (AIEC) reduced gut inflammation in controlled preclinical models.
- The phages did not eradicate the bacteria but switched off a genetic promoter (fimS) that controls the FimH adhesion 'grappling hook', preventing bacterial attachment and lowering immune activation.
- A single phage, HER259, relieved colitis in gnotobiotic mouse models but stopping treatment allowed the fimS promoter to revert and inflammation to return.
- When paired with a common corticosteroid, the phage allowed researchers to use a lower drug dose while preserving therapeutic benefit, indicating potential for dose‑sparing and fewer steroid side effects.
- The targeted bacterial function is measurable in stool and is enriched in a subset of Crohn’s patients, and the team plans broader strain surveys, phage cocktail development, biomarker validation, and steps toward human trials.