We have more bacteria in our bodies than human cells, the vast majority of those microbes in our digestive system, and normally we all get along fine.
That bacteria in our gut – including the small intestine and colon – does a lot of good things for us, helping the body break down food and absorb nutrients among them.
The system relies on the body curbing its natural defenses against foreign invaders.
"The body sees a challenge, it reacts to it and then shuts off," is the way Carle Foundation Hospital's Dr. Gene Greenberg put it recently.
But in some people, the response by the body's immune system doesn't reach what University of Illinois Professor Rex Gaskins characterized as "detente" with the bacteria. Instead of reaching a state of equilibrium, the body keeps fighting the microbes, good for us or not, resulting in conditions such as Crohn's disease and ulcerative colitis, so-called inflammatory bowel diseases.
The maladies affect more than a million Americans in ways that can range from annoying to debilitating and may require surgery.
"It's a very uncomfortable disease," Gaskins said of Crohn's, which commonly affects the lower part of the small intestine. "It really affects quality of life."
Gaskins, Greenberg and colleagues are embarking on a study involving the UI's new Institute for Genomic Biology and Carle that may help uncover the molecular mechanics of Crohn's and, eventually, lead to more effective ways of treating it.
The researchers are looking for people to participate in the study, both folks with Crohn's and those who don't suffer from the disease but are planning to undergo a routine screening colonoscopy. Anyone interested in participating should contact Melody Barber at Carle, 217-383-3610.
The study is being funded by the UI and Carle's Translational Research Program, which is designed to leverage scientific research done at the university in conjunction with Carle physicians to improve medical treatment.
Crohn's is a complex disease for which current treatments seem to be effective only for some patients. Part of the problem is that the disease "can take such a variety of courses from highly aggressive to an annoying thing," Greenberg said.
Ideally, doctors would like to know if there are identifiable factors that predispose a patient to one extreme or another in order to better plan a course of treatment, he said.
There certainly are indications that genetics play a role in whether someone develops Crohn's or not, said Gaskins and UI professors Steven Blanke and Richard Tapping, who also are involved in the study. Among other things, the malady has been shown to be rare in Asians and South Americans and less common in people of African descent. Jewish people are at greater risk, as are people who have a family member with the disease.
One gene, part of the immune system, already has been associated with Crohn's, although multiple genes are more than likely involved. The microbial mix in a person's gut also is probably a factor.
Enter the UI researchers, including professors Roderick Mackie and Sheng Zhong and graduate students Gerardo Nava and Jennifer Croix, who's working on both her doctorate and her medical degree through the UI Medical Scholars Program.
The cross-disciplinary team, the kind of effort the UI Institute for Genomic Biology was designed for, plans to look at genes involved in both sensing gut bacteria and creating barriers to them that prevent the body from reacting excessively.
The researchers also are going to collect, in essence, DNA fingerprints of the various bacteria found in the study's participants.
The idea is to compare those factors among Crohn's sufferers and in people without the disease, with one goal to better understand what may predispose someone to Crohn's.
Carle already has funded a pilot study used to develop the methodology. The pilot study examined 20 people undergoing routine screening colonoscopies. The new study will look at hundreds of participants with and without Crohn's.