Many studies have reported changes in gut microbiome composition in patients with inflammatory bowel disease, including ulcerative colitis, when compared with healthy individuals. While that clearly raises the question about the key role played by gut microbes in IBD pathogenesis, we have yet to pinpoint the causative microbes and their mechanisms.

A recent randomised placebo-controlled trial, led by Prof. Thomas Borody from the Centre for Digestive Diseases in Sydney (Australia), has found that faecal microbiota transplantation induces clinical remission and endoscopic improvement in patients with active ulcerative colitis.