Lay Summary

Proposal No.  IBD-0032
Principal Investigator: Timothy Florin, MBBS
Applicant Organization: The University of Queensland (Brisbane, Australia)
Project Title:  Mucosal bacterial pathogens in inflammatory bowel disease
Period of Award:  December 1, 2002 – February 28, 2005

Crohn's disease and ulcerative colitis are chronic and often debilitating inflammatory bowel diseases (IBD).  IBD affects approximately 0.4% of Australians and Americans.  The cause of these diseases is unknown, but it is agreed that bacterial products instigate or drive the inflammation.

We are testing the hypothesis that specific enteric bacteria are associated with Crohn's disease and ulcerative colitis.  These putative bacterial pathogens are located in the lining (mucosa) of the intestines - a part of the body that hosts a complex microbial population in normal healthy individuals.  Many of these bacteria are unculturable, thereby limiting research in this field.  We are using molecular microbial ecological techniques to overcome this problem and to test the hypothesis.  The specific bacteria may induce inflammation and thus cause IBD, by a mechanism analogous to Helicobacter pylori infection, which is now known to cause peptic ulcer diseases.

We have exciting preliminary data that indicate that the population of mucosal bacteria is different in Crohn's disease compared with patients without IBD.  Furthermore, we have found novel bacterial sequences that are associated with Crohn's disease intestine.

The discovery of IBD-associated bacteria may revolutionize treatment of IBD, just as the discovery of Helicobacter pylori has revolutionized treatment of peptic ulcer diseases.