Scientists have discovered an unexpected cancer-fighting agent in the gut of a frog. A study published in the journal Gut Microbes reports that a bacterium isolated from the Japanese tree frog can completely eliminate colorectal tumors in mice after just one dose, opening a new direction for cancer therapy research.
A Microbe That Actively Targets Tumors
Researchers identified the bacterium, Ewingella americana, while screening dozens of microbial strains collected from the digestive systems of amphibians and reptiles. Unlike most bacteria, this microbe actively migrates toward tumors after doctors inject it into the bloodstream. Because solid tumors contain low-oxygen environments, the bacterium thrives there and rapidly multiplies inside cancerous tissue while sparing healthy organs.
How the Bacterium Attacks Cancer Cells
Once the bacterium reaches the tumor, it launches a two-pronged attack. It directly damages cancer cells and simultaneously triggers a strong immune response. The invading microbe draws immune cells, including T cells and neutrophils, into the tumor, where they intensify the assault on cancer. As a result, the immune system joins the bacterium in destroying the tumor from within.
Single-Dose Success in Mouse Models
In laboratory experiments, researchers administered a single intravenous dose of Ewingella americana to mice with colorectal cancer. The treatment completely erased tumors in all treated animals. When scientists later exposed the same mice to cancer cells again, the animals resisted tumor growth, showing that the therapy also trained the immune system to recognize and fight the disease.
Early Research With Major Potential
Although the results are striking, researchers emphasize that the therapy remains in the preclinical stage. Scientists must conduct extensive safety and efficacy studies before testing it in humans. Even so, this discovery highlights how naturally occurring microbes could become powerful, targeted cancer treatments that work by both killing tumors and strengthening immune defenses.
