Inflamed intestines produce their own brand of fertilizers, which nourish E. coli and other disease-associated bacteria, a new study shows.
Everyone carries a small amount of E. coli in their intestines, and it normally causes no problems. But compared with people who have healthy colons, people with inflammatory bowel diseases such as ulcerative colitis or Crohn’s disease harbor a mix of intestinal microbes that is heavier on E. coli.
No one knew whether the disease or the altered microbial mix came first. The new study, published in the Feb. 8 Science, takes a step toward unraveling that chicken-or-egg tangle. Inflammation, a process the body usually uses to kill microbes, may instead feed “bad” bacteria, further inflaming the gut.
Scientists know that during inflammation, tissues produce chemicals such as nitric oxide and superoxides, which can break DNA and ravage bacterial cells. But in experiments involving mice, Andreas Bäumler of the University of California, Davis and colleagues discovered that when the chemicals react with each other, they can produce nitrates and other compounds that some bacteria use for fuel.