Changed bacteria attack tumors in mice with less harm
Original title: Expanding the therapeutic window of bacteria for cancer therapy
How far along is this research?
This is a preprint. Other scientists have not checked it yet, so treat it as an early signal rather than an answer.
This was only done in mice.
The short version
Scientists built a safer tumor-fighting germ, but so far only in mice.
What was studied. Researchers changed bacteria so they would grow only inside tumors and set off less of an immune reaction. They tested the new strain in mice, including mice with colorectal cancer and mice with glioblastoma: A glioma that is given grade 4. Grade 4 is the highest grade there is. The tumor grows fast. Treatment usually starts soon after it is found. It often means surgery, and then radiation and chemotherapy. See the glossary.
What they found. The changed bacteria could be given in much larger amounts before causing harm. The safe dose rose by as much as 1,000-fold, depending on how it was given. The bacteria shrank tumors on their own and also worked as a way to deliver drugs. When they carried an immune drug, up to 75% of colorectal tumors went away and stayed away.
What this means, and what it doesn't
What it could mean: This points to a possible new way to treat tumors from the inside, using bacteria as the delivery truck. It is early lab work in animals. There is nothing here a patient can ask a doctor for today.
What it doesn't mean: This is not a new treatment for brain tumors. The work was done in mice, not in people. The best tumor results were in colorectal tumors, not brain tumors. We do not know if it is safe or helpful in humans. It is not a promise of a cure.
Source: bioRxiv (preprint), October 29, 2026 · Read the original
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