Targeting ‘sticky’ bacteria E.coli

What the research looked at?

There is strong scientific evidence that a reduction in 'good' bacteria and an increase in the number of 'bad' bacteria in the gut are key factors in the development of Inflammatory Bowel Disease (IBD). 

A number of studies have identified an adherent (sticky) bacteria called Escherichia coli (E.coli) in both the small and large intestines of people with Crohn's. They have found that E.coli moves into cells across and into the gut wall by 'travelling through' naturally occurring microfold (M) cells. Collections of these M cells within our bowel monitor both good and bad bacteria, supporting our bodies defence systems in recognising and dealing with infection. Once the E.coli bacteria reach the inside of the gut, immune cells called macrophages would normally kill infections. But in people with Crohn's, the function of these macrophage cells seems to be impeded and/or the bacteria themselves seem able to resist being killed. That means the bacteria survive and increase in numbers. 

This study aims to look at how E.coli reacts with proteins on the surface of M cells to allow the bacteria across and into the gut wall. It will also look at whether people with IBD tend to have higher numbers of the M cells that are assisting E.coli infection. The researchers hope that blocking bacteria from entering through the M cells could be a potential target for therapies. 

Conclusions: Before starting the project, the researchers knew that there is a protein on the surface of the E.coli that helps them to target, stick to, and move into, M cells. However, the research team did not know where or how exactly this sticky protein on the Crohn’s-associated E. coli attached to the M cells. During this project the researchers identified three sugary-fat ‘glycolipid’ structures on the surface of the M cells that the E.coli sticky protein binds to. In future studies, the researchers hope to investigate whether people experiencing an IBD flare have more of these ‘glycolipids’ on their bowel M cells. This might help to explain the increased numbers of these inflammation-causing E.coli seen in people with Crohn’s. The researchers will also investigate whether drugs or dietary approaches can be used to block the binding of the sticky E.coli to the M cells. 

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

The researchers hope that studying the mechanism of E.coli may lead to developing a new way of treating Crohn’s Disease. 

Who is leading the research: Professor Barry Campbell, University of Liverpool 
Our funding: £78,000 over 18 months 
Official title of the application: "Identifying intestinal receptors for Crohn's Escherichia coli."
Tags: Bacteria