A team of researchers from the University of Minnesota, along with international collaborators, has found that intestinal bacteria responsible for Crohn’s disease and ulcerative colitis (known as inflammatory bowel disease (IBD)) can be inherited by some individuals.
The work, published in the journal Genome Medicine, has also established that antibiotics have the capacity to exacerbate the imbalance in gut microbes.
There are approximately 1.6 million Americans diagnosed with Crohn’s disease or ulcerative colitis.
The majority of colorectal cancers occur through sporadic mutations in genes responsible for regulating the epithelial cell cycle and survival. Moreover, environmental risks such as high-fat diets, sedentary occupations and obesity all account for increased risk. However, the most immediate environmental factor predisposing to colorectal cancer is the gut microbiota, which is in part defined by these lifestyle variables.
There have been several animal studies that partly explain the complexity of the microbiota in the development of inflammation and cancer. Furthermore, a previous clinical study in humans has shown that teenagers with high levels of inflammation had an associated 63% higher risk of developing colorectal cancer, when compared to patients with normal inflammation levels.
“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,” study’s lead author Dr. Dan Knights, a University of Minnesota assistant professor in the Department of Computer Science and Engineering and the Biotechnology Institute said in a news release. “We have found groups of genes that may play a role in shaping the development of imbalanced gut microbes.”
A total of 474 adults with IBD from 3 different geographical locations participated in the study. Researchers collected and analyzed intestinal DNA samples from each participant, identifying several different microbial species and human genes.
The results demonstrated that human DNA was correlated to the bacteria found in their intestines. Importantly, patients with IBD presented a smaller bacterial biodiversity and had a higher number of opportunistic bacteria.
“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,” Dr. Knights added in the news release.