Inflammation drives Crohn's disease, says study

August 16, 2012
Inflammation drives Crohn's disease, says study
A new study shows that inflammation drives dysbiosis, Gram negative proliferation and E. coli invasion.

Inflammation -- not genetic susceptibility -- drives the growth of intestinal bacteria and invasive E. coli linked to Crohn's disease (CD), reports a new Cornell study.

Scientists have long wondered about the role of bacteria in CD. Recent studies have shown marked changes in the composition of the in people with CD, leading researchers to ask: Are microbial abnormalities a direct consequence of linked to Crohn's and precede and initiate inflammation, or does intestinal inflammation bring on the bugs?

Inflammation, in fact, drives microbial imbalances (dysbiosis) and the proliferation of a specific type of E. coli that is adherent, invasive and found in the ileum, reported Cornell researchers July 31 in PLoS (7[7]). And genetics, they said, do play a role in determining the threshold and magnitude of dysbiosis in response to induced by environmental triggers.

This study also reports that a common therapy directed against intestinal inflammation decreases dysbiosis. In addition, the study found that the lack of a receptor that helps recruit , which are needed for cell-mediated immunity, to the gut also decreases inflammation and dysbiosis, offering a new option for therapeutic intervention.

"Today, remission is our mission," said Kenneth Simpson, professor of small animal medicine at Cornell's College of Veterinary Medicine and principal investigator. "Crohn's disease is a highly complex condition that finds its strength in the combination of negatives: environmental factors, and immune system malfunctions. Ultimately, there may be a cure. Until then, we need to find ways to relieve suffering."

CD is a chronic debilitating that involves a complex interaction of , the immune system, the intestinal microbiome and the environment. Afflicting more than half a million people in North America, CD can trigger mild to severe diarrhea, fever, fatigue, anemia, reduced appetite and weight loss.

To mirror the complex nature of the disease, Simpson's team designed a study that incorporated inflammatory triggers related to relapse of CD and ileal inflammation. Unlike previous studies that have focused on colonic or fecal dysbiosis, the team focused on ileal dysbiosis, which is prevalent in 70 percent of CD cases. Also novel to this study, the team used a variety of contemporary techniques to generate a comprehensive picture of the composition and spatial distribution of the ileal microbiome. Particular attention was paid to pinpointing the number, pathotype and location of E. coli associated with in people, dogs and mice.

"Our findings clearly demonstrate that inflammation drives ileal dysbiosis and proliferation of CD-associated adherent invasive E. coli. Further, in the context of a patient with Crohn's, we found that the host genotype and therapeutically blocking both impact the onset and extent of ileal dysbiosis. These novel findings are of high relevance to Crohn's disease."

The investigation leveraged the knowledge and resources of researchers in the labs of Erik Denker, Dwight Bowman and Sean McDonough labs. Building on findings in patients with Crohn's disease evaluated by Dr. Ellen Scherl's group at Weill Cornell Medical College, this collaboration shed new light on this debilitating disease.

"It appears that we harbor our own powder keg," said Simpson. "The bacteria are already seeded. It's what controls the relative balance between the different species of bacteria and their numbers, relative proportions, our ability to deal with them, and the cross-talk between the bacteria and host that is important."

Explore further: Researchers pinpoint role of key proteins in Crohn's Disease

Related Stories

Researchers pinpoint role of key proteins in Crohn's Disease

June 14, 2011

(Medical Xpress) -- Researchers at the University of Toronto have discovered the role the interactions between key proteins plays in the body’s response to Crohn’s Disease - a revelation that may lead to the development ...

Recommended for you

Zika virus infection alters human and viral RNA

October 20, 2016

Researchers at University of California San Diego School of Medicine have discovered that Zika virus infection leads to modifications of both viral and human genetic material. These modifications—chemical tags known as ...

Food-poisoning bacteria may be behind Crohn's disease

October 19, 2016

People who retain a particular bacterium in their gut after a bout of food poisoning may be at an increased risk of developing Crohn's disease later in life, according to a new study led by researchers at McMaster University.

Neurodevelopmental model of Zika may provide rapid answers

October 19, 2016

A newly published study from researchers working in collaboration with the Regenerative Bioscience Center at the University of Georgia demonstrates fetal death and brain damage in early chick embryos similar to microcephaly—a ...

Scientists uncover new facets of Zika-related birth defects

October 17, 2016

In a study that could one day help eliminate the tragic birth defects caused by Zika virus, scientists from the Florida campus of The Scripps Research Institute (TSRI) have elucidated how the virus attacks the brains of newborns, ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.