What Is the Role of the Environment (Exposome) in Inflammatory Bowel Disease?

Abstract

OPENING Day 2 of the 17th Congress of European Crohn’s and Colitis Organisation (ECCO), James Lindsay, Professor of Inflammatory Bowel Disease, Barts Health NHS Trust, London, UK, and The London School of Medicine, Queen Mary University of London, UK, discussed the influence of the environment on the risk of developing inflammatory bowel disease (IBD). The presentation discussed the pathways that mediate environmental impact on IBD as well as the limitations of presently available research, giving a valuable insight into what future studies could be conducted to ultimately determine the role of environmental factors in IBD. The present understanding of IBD, an inflammatory disease, which includes Crohn’s disease (CD) and ulcerative colitis (UC), is that the condition arises from an immune response to micro-organisms of the intestinal flora in genetically susceptible individuals. In addition to disease pathogenesis, other important aspects such as progression, extraintestinal manifestations, and immunogenicity to therapies, are yet to be well understood. While the genetics base is clear, it does not account for the discordance of disease in monozygotic twins, the increased incidence in second generation immigrants, or the rapid increase in IBD cases in the last 50 years. In light of these observations, Lindsay expressed the importance of examining the role of the environment, which, he stressed, does not comprise a single factor, but a multitude of factors that are likely to impact disease onset and natural history.