Does an abnormal way of dealing with gut bacteria lead to Crohn’s Disease?

What the research looked at? 

Researchers have long thought that an abnormal reaction to bacteria may play a role in developing Inflammatory Bowel Disease. 

One of the signs of Crohn’s Disease is the formation of granulomas on the bowel wall. Granulomas are formed when immune cells collect around a foreign substance (for example, bacteria), and try and wall them off from the rest of the bowel and isolate them – creating a ‘nodule’ or lump. They are more commonly found in younger Crohn’s patients, and often are associated with more aggressive disease and more frequent relapses. 

There are multiple factors which may lead to granuloma formation – the genes a person has inherited, along with bacteria, and also the inflammatory molecules found within the gut. In general, there are multiple genes connected with Crohn’s. However, there are also a number of other diseases which also cause inflammation in the gut, but which are only controlled by one gene. An example is chronic granulomatous disease (CGD), which causes granulomas to form. 

The researchers wanted to compare the granulomas in Crohn’s Disease and the granulomas in chronic granulomatous disease in order to understand the processes which lead to the formation of granulomas in the gut. They aimed to identify and screen the bacteria, genetic and inflammatory factors which may lead to the formation of granulomas. Ultimately, they wanted to use this information to develop a new treatment for Inflammatory Bowel Disease patients which targets how the gut handles bacteria. 

Conclusions 

The presence of granuloma is a hallmark of Crohn’s Disease. The researchers have investigated the formation of granuloma and the conditions needed for these cell clusters to develop. They have found that the presence of bacteria is linked to the formation of these granuloma and by isolating DNA from the affected cells, they will be able to identify the specific bacteria present. With this information, they can undertake further research looking at the role of these bacteria and potential treatments to stop granuloma formation. 

What do the researchers think this could mean for people with IBD? 

The researchers hope that they will be able to understand what leads to granuloma formation in Crohn’s patients. If they can find out why granulomas form, the research may lead to new treatments for Inflammatory Bowel Disease which target how the gut handles bacteria, rather than the standard immunosuppressive drugs currently used. 

Who is leading the research: Dr Holm Uhlig, University of Oxford, John Radcliffe Hospital
Our Funding: £10,000 (funded by for Crohns)
Duration: 12 months 
Official title of the application: Understanding granuloma formation in Crohn's disease and monogenic inflammatory bowel disease
Tags: Bacteria