Dissecting Dysbiosis in Inflammatory Bowel Disease.

The human intestine is home to trillions of bacteria of hundreds of different types, which are collectively referred to as the gut microbiota. Ideally, these microbes exist in a balanced state, where both microbe and man benefit from their presence. However, imbalances in the microbiota, which are referred to as ‘dysbiosis’, have been suggested to underlie the development of a variety of inflammatory diseases, including IBD. While there is broad consensus that microbiota composition in patients with IBD differs from healthy controls, it remains unknown whether this dysbiosis is a cause or effect of the imbalanced immune responses that underlie IBD development. Here, we propose to use a new model system to experimentally examine the effect of dysbiosis in patients with IBD on the gut immune system. These studies will reveal whether imbalances in the gut microbiota play a causal role in the immunological imbalances that trigger IBD development, and will reveal potential mechanisms by which we can correct dysbiosis to prevent or cure IBD in the future.