McMaster researchers identify long unknown bacteria strain believed to trigger Crohn’s disease

Researchers at McMaster University have identified a long unconfirmed strain of bacteria that is believed to be a potential trigger of Crohn's disease.

Adherent-invasive E. coli (AIEC) - which develops in a biofilm that coats cells in the inner intestinal wall - is typically found in 70 to 80 per cent of positive Crohn's patients.

But how it grows and why it prompts the immune system to switch off its inflammatory response to gut bacteria has been unknown for decades.

That is, partly, until now.

After mutating every gene in a particular strain of AIEC and testing those mutants in mice, researchers from McMaster and Harvard University were able to discern which genes allow AIEC to unabatedly colonize the intestinal walls of Crohn's patients.

The researchers - led by Brian Coombes, chair and professor of McMaster's department of biochemistry and biomedical sciences - found a critical protein structure on the surface of AIEC that allows them to grow in biofilms.

While present treatments for Crohn's look to ease inflammation, none address the root cause of the disease.

Coombes said identifying the AIEC strain will spur a host of new ways to treat the condition.

(W) e are one step closer to figuring out how this Crohn's disease-associated bacteria lives in the gut and when we do that, we can develop new treatments," he said.

Sebastian Bron is a Hamilton-based reporter at The Spectator. Reach him via email: sbron@thespec.com