Researchers might have just stumbled upon a potential answer to why younger adults are getting more colorectal cancer—without trying.

An international team of researchers has identified a potential microbial culprit behind the alarming rise in early-onset colorectal cancer: a bacterial toxin called colibactin. Scientists report that exposure to colibactin in early childhood imprints a distinct genetic signature on the DNA of colon cells--one that could significantly increase the risk of developing colorectal cancer before the age of 50.

A new study has suggested childhood exposure to a gut toxin could be behind a spike in early-onset colorectal cancer. Colibactin, produced by some E. coli strains, “imprints a distinct genetic signature on the DNA of colon cells — one that may increase the risk of developing colorectal cancer before the age of 50,