Inherited Gut Bacteria Drives Crohn's Disease and Ulcerative Colitis

A team of researchers recently reported that human genes may partially influence intestinal bacteria spurring inflammatory bowel disease (IBD) conditions like Crohn’s disease (CD) and ulcerative colitis (UC).

In study results published in Genome Medicine, the study’s lead author, Dan Knights, an Assistant Professor in the Department of Computer Science and Engineering and the Biotechnology Institute at the University of Minnesota, noted that antibiotics could potentially exacerbate any existing gut microbe imbalance.

“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. We have found groups of genes that may play a role in shaping the development of imbalances gut microbes,” said Knights.

Over a 2-year period, the researchers examined 3 independent cohorts (from Boston, MA, Toronto, ON, and Croningen, Netherlands) of 474 adults afflicted with IBD, gathering their DNA samples as well as the DNA of their intestinal bacteria. The authors wrote, “We tested for correlation between relative abundance of bacterial taxa and mumber of minor alleles at known IBD risk loci, including fine mapping of multiple risk alleles in the Nucleotide-binding oligomerization domain-containing protein 2 (NOD2) gene exon.”

Studying a multitude of microbial species and human genes, the results indicated that the DNA was directly linked to intestinal bacteria. IBD patients exhibited lower bacteria biodiversity and more “opportunistic” bacteria, which stimulate the foray to begin developing targeted drug treatments.

While previous studies had reported links between human gut bacteria and increased risk of a large array of diseases including diabetes, autism, heart disease, and even some forms of cancer, this study confirmed the relationship between antibiotic use and intestinal bacterial imbalance.

Knights stated, “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 unravelling the mystery.”