Two microbes appear to work together in the gut to feed the development of colon cancer, the New York Times reports.
Researchers led by Johns Hopkins University's Cynthia Sears initially sought to examine a toxin produced by one of the microbes, Bacteroides fragilis, the Times says, but the researchers found that the toxin harmed cells in vitro and promoted cancerous changes. This, it adds, spurred the researchers to investigate whether there were any gut bacteria linked to colon cancer.
As Sears and her colleagues report this week in Science, they examined the colonic mucosa of people with adenomatous polyposis, who often develop benign lesions early in life to uncover biofilms harboring mostly B. fragilis and Escherichia coli. The researchers also noted high levels of B. fragilis toxin and colibactin in these individuals as compared to controls. In tumor-prone mice, the combination of B. fragilis and E. coli prompted increased and faster tumor development than in mice only given one of the bacterial species.
While this suggests eliminating B. fragilis and E. coli from patients' colons could protect them from disease, Sears tells the Times it's premature to do so.
"You could try to eliminate the bugs," the University of Florida's Christian Jobin tells the Times. "That is easy to say, but hard to do. Antibiotics will probably do more damage than good."