Solving a 15-year mystery: Scientists discover how gut bacteria toxin invades colon cells to trigger cancer

Since a landmark 2009 study, researchers have known that a common gut bacterium, Bacteroides fragilis, drives colon tumor formation, potentially leading to colorectal cancer, by secreting a toxin that damages the lining of the colon. But until now, the exact mechanism the toxin uses to latch onto those cells remained a mystery.