Dr Holm Uhlig talks about the role of the immune system in our gastrointestinal tract. The gastrointestinal tract is home to more bacteria than there are cells in our body. In order to stay healthy, our immune system must maintain a strong and effective response towards these bacteria. Dr Holm Uhlig is based at the Translational Gastroenterology Unit and studies defects in the immune response and regulation leading to immunopathology. Dr Uhlig is predominately interested in children with inflammatory bowel disease, and aims to understand the complex puzzle of molecular mechanisms involved. Creative Commons Attribution-Non-Commercial-Share Alike 2.0 UK: England & Wales; http://creativecommons.org/licenses/by-nc-sa/2.0/uk/