Researchers from the Gladstone Institute have tracked and associated the progression of inflammatory bowel disease (IBD) with parallel changes in what gut bacteria are doing over time. Their work was published yesterday in mSystems.
Initially, the scientists wondered if bacteria are responsible for causing IBD, or if IBD causes bacteria in the gut to change. To answer this question, a collaboration started between Shomyseh Sanjabi, Ph.D., an assistant investigator at Gladstone, and a biostatistician, Katie Pollard Ph.D., director of the Convergence Zone at Gladstone.
In this study, researchers monitored the mice's immune system and collected fecal bacteria on a weekly basis and then analyzed the full DNA sequence of these bacteria.
"We detected changes in the genes of the gut bacteria before any symptom of IBD appeared," says Sanjabi, who is also an assistant professor at the University of California, San Francisco. "Most of the changes in bacteria happened at the same time as the immune system started showing signs of an autoimmune disease. This model can help us identify exactly when the disease starts."
With their results, the scientists found that these changes in the microbiome may represent an early indicator of the disease. Current therapies for IBD only treat symptoms, but not the root of the problem. If researchers can pinpoint the early signs of the disease, they may be able to develop diagnostic tools and find treatments to address the disease.
Sanjabi and Pollard suspect that IBD is caused by the dynamic interaction between an abnormal immune response and opportunistic bacteria. Their next step will be to test whether they can trigger IBD by manipulating specific gut bacteria.
"I'm encouraged by our promising results," says Pollard. "We could potentially analyze the microbiome of patient stool to classify and even predict disease. That would be an enormous step in the right direction."