Host genetic susceptibility, dysbiosis, and viral triggers in inflammatory bowel disease

Purpose of review Inflammatory bowel disease (IBD) is thought to occur in genetically susceptible individuals. However, environmental factors, potentially including shifts in commensal microbiota, are also required to trigger disease. This review discusses some of the recent discoveries in host susceptibility and interaction with the microbial environment, and pinpoints key areas for advancement in our understanding of IBD pathogenesis. Recent findings Meta-analyses of genome-wide association studies have uncovered many new exciting genes associated with susceptibility loci for IBD. In addition, improved methods to analyze the commensal microbiota pave the way to better define dysbiosis and its potential role in disease. Lastly, identification of viral triggers in experimental systems suggests a potential role for viral infection in IBD. Summary Understanding the precise microbial and immune triggers of IBD in a genetic context will hopefully lead to a better understanding of the pathogenesis of this disease and the discovery of novel therapeutic approaches, including vaccination against specific viruses.