Bacteria responsible for 'inflammatory bowel diseases' identified

In a new study, possible bacterial culprits behind inflammatory bowel diseases (IBD), such as Crohn's disease and ulcerative colitis, have been identified.

Trillions of bacteria exist within the human intestinal microbiota, which plays a critical role in the development and progression of IBD. Yet it's thought that only a small number of bacterial species affect a person's susceptibility to IBD and its potential severity.

Researchers at Yale University focused on antibody coatings on the surface of bacteria. In particular, the team looked at bacteria with high concentrations of an antibody coating called Immunoglobulin A (IgA).

The scientists confirmed a correlation between high levels of IgA coating and inflammatory responses in the human intestine. To do this, the team collected 'good' and 'bad' bacteria from a small group of patients and transplanted them into mice.

While in healthy mice there was no influence on intestinal inflammation, in mice with induced colitis, those with the suspected 'bad' bacteria showed signs of excessive inflammation and other IBD symptoms.

Richard Flavell, the Sterling Professor of Immunobiology at the University, said that the study's results indicated that anti-bacterial therapies for IBD were possible. Such anti-bacterial approaches might include highly specific antibiotics, vaccines, and probiotics.

The findings are published in the journal Cell.