Cancer ResearchJohns Hopkins team finds how a gut bacterium toxin attacks the colon and drives cancer
Colorectal cancer risk is shaped partly by the bacteria living in our gut. Johns Hopkins researchers have solved a nearly two-decade-old puzzle about how one common species, Bacteroides fragilis, can contribute to it. Some strains make a toxin called BFT that breaks down E-cadherin, a protein that holds colon cells together and keeps the gut lining intact. Until now, no one knew how the toxin first latched onto colon cells. Using CRISPR gene editing, the team found that a protein called claudin-4 serves as the toxin's docking point. They then built a molecular decoy that intercepts BFT before it can do harm, and it protected mice from the toxin's effects. About 20% of healthy people carry B. fragilis, and carrying it does not mean cancer will develop. The work, published in Nature, is early preclinical research, but it points to new ways to detect and prevent bacteria-linked colon damage.
