A new study on inflammatory bowel disease (IBD) entitled “Complex host genetics influence the microbiome in inflammatory bowel disease” was recently published in Genome Medicine by Dr. Dan Knights from University of Minnesota’s Department of Computer Science and Engineering and the Biotechnology Institute. In this study, Dr. Knights and colleagues found that patients with inflammatory bowel disease (IBD), such as Crohn’s disease and ulcerative colitis, can inherit the ‘gut’ bacteria that cause the pathologies.
According to the Crohn’s and Colitis Foundation of America, 1.6 million Americans have Crohn’s disease or ulcerative colitis. Therefore, better knowledge of the pathogenesis of these diseases will improve their prevention and treatment. Inflammatory bowel disease (IBD) susceptibility has been associated with the interactions between host genetics and type of host-microflora in the gut. However, there has been no direct comparison between complex genome-microbiome associations in large groups of patients with an immunity-related disease.
“The intestinal bacteria, or ‘gut microbiome,’ you develop at a very young age, can have a big impact on your health for the rest of your life,” said Dr. Dan Knights, in a press release. “We have found groups of genes that may play a role in shaping the development of imbalanced gut microbes.”
In this study, Dr. Knights and colleagues from the University of Minnesota, Broad Institute at Harvard, MIT, University of Toronto and University Medical Center Groningen analyzed three independent cohorts with a total of 474 adult patients with IBD living in Boston, Mass. (USA); Toronto, Ontario (Canada); and Groningen (Netherlands). The clinicians collected samples of DNA from each patient and the DNA of the respective intestinal bacteria during 2 years and analyzed thousands of microbial species and human genes. The data demonstrated that the DNA from the patients was associated with the DNA of the bacteria in their gut. The patients with IBD had lower diversity of bacterial strains and higher levels of opportunistic bacteria. This information is important to develop therapies that can target specific genes or bacterial compounds from the gut bacteria.
The biodiversity of gut bacteria is dependent on genetics, age, gender, medication and other variables. This study also highlighted that the use of antibiotics is linked with changes of equilibrium in the microbiome of the gut. Other studies have already shown associations between human gut bacteria and high risk of developing diseases like diabetes, autism, heart disease, and some types of cancer.
“In many cases we’re still learning how these bacteria influence our risk of disease, but understanding the human genetics component is a necessary step in unraveling the mystery,” said Dr. Knights.
This research was funded by the National Institutes of Health (NIH), the National Science Foundation, the Crohn’s and Colitis Foundation of America and the Crohn’s and Colitis Foundation of Canada.