Genetic Data Now Available for Bacteria Central to Chron's Disease

Comprehensive sequencing effort could reveal how bacteria cause gut wall damage

Scientists have made genetic data publicly available for bacteria that might be lurking inside the gut walls of patients chronically affected with severe Crohn’s disease.

By studying a surgically removed, damaged bowel from a patient, researchers were able to culture bacteria from a special form of microscopic lesions that they earlier discovered and that can be present within the gut wall of the inflamed bowel in Crohn’s disease. After growing the bacteria in their laboratory, they chose one representative species, and performed a complete genome sequence analysis that could hold clues into how the slow and damaging microlesions form.

The bacterium’s sequence, announced online via the American Society for Microbiology, corresponds to a microbe called Parabacteroides distasonis, and represents the first available genome from a microorganism isolated from microlesions in Crohn’s disease. Thanks to modern sequencing methods, researchers were able to decipher the complete genome, which is now available for others to explore.

The lesions, described by the researchers as “cavernous fistulous tract microlesions,” intriguingly follow the structural principles of how geologic sinkholes and caves form in mountains, but at microscopic scales. The isolation of this bacterium from these cavitating lesions indicates that such microscopic places could serve as a haven for bacteria. Even species traditionally thought to be harmless in the human gut—like P. distasonis—under such circumstances could exacerbate the expansion and progression of such lesions in the inflamed gut.

“The gut wall of a person should not have microscopic cavitations, nor bacteria that are often difficult to grow in the laboratory,” said senior author Alexander Rodriguez-Palacios, assistant professor in the Digestive Health Research Institute at Case Western Reserve University School of Medicine. “The presence of this bacterium inside the gut wall is not normal, especially when you realize that patients have received multiple forms of treatments, including antibiotics, before they are sent to the operating room as an option to temporarily alleviate their disease and pain.”

Read more about genetic data now available for bacteria central to Chron's Dise…