Which ‘bad’ bacteria in the gut can lead to inflammation?


Researchers are looking at the genes of the hundreds of types of bacteria naturally present in the gut.


Research on inflammatory bowel disease and, in particular, Crohn's disease, is now focusing on the role of gut bacteria

Prof Brian Henderson, University College London

What the research is looking at:

We all have hundreds of naturally occurring bacteria in our gut. Some of these are harmless ‘good’ bacteria that help with digestion, while others are not so harmless ‘bad’ bacteria, which may contribute to causing diseases.

Research is now focusing on the role of these bacteria in Inflammatory Bowel Disease, in particular Crohn’s Disease. There is emerging evidence that bacteria in the gut may secrete proteins which interact with the cell layer lining the colon. These proteins may cause inflammation and lead to the development of Crohn’s.

Unfortunately, it is hard to identify which of the bacteria are responsible for secreting these harmful proteins because there are hundreds of different types of bacteria in the gut, and these would all need to be studied individually. Also, at least half of the bacteria present in the colon cannot be grown in the laboratory.

However, scientists have developed a method of getting round these problems by studying the proteins produced by the bacteria using a technique called ‘phage display’. Phages are viruses that infect bacteria, which can be genetically modified in a particular way so that they display the bacterial proteins on their surface. These can then be used to see which proteins interact with the cell lining of the colon – and thus which bacteria may be associated with Crohn’s Disease.

Conclusions: This is an ongoing study, with no conclusions as yet.

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

Researchers hope that they will be able to identify the bacteria in the colon which may cause gut inflammation, and possibly trigger Crohn’s Disease. If they are able to identify these bacteria, then they may be able to target these bacteria in order to treat Crohn’s Disease, or reduce its symptoms.

Who's leading the research: Prof Brian HendersonDr Frank Kaiser, University College London.

Our funding: £119,602 over 24 months

Official title of the application: “Identification and characterisation of the protein interactome of the colonic microbiota and the epithelium in Crohn’s disease using metagenomics.”

Tags: Genetics / Bacteria