Setting It Level · Viral Post Fact Check ·
Engineered gut bacteria wiped out 43% of colorectal tumors in mice.
What We Found
A 2026 Columbia study in Science Translational Medicine engineered the probiotic E. coli Nissle 1917 to make chemotherapy (5-FU) plus immune boosters inside tumors.
In a colorectal cancer mouse model, 3 of 7 treated tumors regressed completely: 43%. Untreated tumors elsewhere also grew more slowly, and cured mice resisted re-exposure.
It was a small mouse study with implanted tumors, and the bacteria were injected directly into tumors.
No human data yet. Researchers say it needs models closer to human cancer and clinic-ready delivery.
Bottom line: real result, 3 of 7 mice, not a cure.
Sources
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