Genes, Viruses, Microbes and IBD

Monday, 09 August 2010 by

Crohn’s disease is common and miserable to suffer from, yet its actual cause is still under some debate as no clear understanding has yet been fully elucidated. It is known that there are some gene variations and that the environment has an impact. A paper out in Cell suggests, based on a mouse model that it may be a virus that makes the difference between health and inflammation. demonstrate that a viral infection, a toxic insult to the gut, commensal bacteria, and a Crohn’s disease susceptibility gene collude to cause inflammatory disease in the mouse gut.[1]

To be clear, Cadwell and co-workers are not arguing that Crohn’s disease is caused by infection with norovirus (as used in this study) or by any other single microbe. The environmental factors that predispose to and protect from Crohn’s disease remain uncertain, but the balance among commensal and pathogenic gut bacteria and viral infections is likely to be part of the story. These studies make an urgent and compelling case for characterising the human virome as well as the microbiome and defining its effects on physiology and gene expression. In addition, further explanations to help us to understand how the virome interacts with polymorphisms in the host genome and how numerous toxins in the environment alter this complex interplay will need to be unravelled.