A sharp rise in early-onset colon cancer may be linked to a dangerous strain of E. coli found in ready-to-eat foods like chopped lettuce, according to new research. Between 2016 and 2023, cases of non-O157 shiga toxin-producing E. coli (STEC) in England rose from 297 to 2,341, affecting over 9,300 people and causing several deaths and serious illnesses.

Researchers found colibactin—a cancer-associated toxin produced by certain E. coli strains—in colon tumors of patients under 40. These cases were 3.3 times more likely to have the toxin than tumors in older patients.