Patients newly diagnosed with inflammatory bowel disease (IBD) show significant changes in their gut bacteria, according to an international study published in Gastroenterology. The research was led by the University of Birmingham and is the first to combine raw microbiome data from several studies, analyzing information from over 1,700 children and adults across 11 countries who had not yet begun treatment.
The study found that people with Crohn's disease and ulcerative colitis, the most common IBD subtypes, lose beneficial anaerobic bacteria responsible for digesting complex carbohydrates. Instead, there is an increase in oxygen-tolerant bacteria typically found in the mouth, such as Granulicatella and Haemophilus, which migrate into the gut.
These results support the "oxygen hypothesis," which suggests that increased oxygen levels in the gut lining may disrupt microbiome balance and contribute to IBD. The findings could lead to new diagnostic tools for earlier detection of IBD and point toward potential treatments targeting the microbiome or modifying oxygen levels in the gut.
Professor Tariq Iqbal, joint senior author of the study and Director of the University of Birmingham's Microbiome Treatment Centre, said: "This study demonstrates the value of collaborative research in the microbiome field. By combining global data and advanced bioinformatics, we're moving closer to personalised, non-drug therapies that could transform how we treat chronic gut conditions like IBD."
Professor Morris Gordon, Co-director of the Biomedical Evidence Synthesis and Translation to practice (BEST) unit at the University of Lancashire, added: "This unique study combined significant clinical, scientific and evidence synthesis expertise to identify the unique conditions in the gut at the time of diagnosing this condition. This opens up avenues to investigate regarding screening, diagnosis and therapies."
The project involved researchers from several institutions including NIHR Birmingham Biomedical Research Centre—funded to improve outcomes for people with inflammatory conditions—as well as collaborators from Australia’s University of New South Wales, NHS Greater Glasgow and Clyde, University of Lancashire, and University of Dundee.
