A bacterium isolated from the intestines of Japanese tree frogs has completely eliminated colorectal tumors in mice with a single intravenous injection, achieving results that outperformed both chemotherapy and immune checkpoint inhibitors in direct comparisons. The finding, published in the journal Gut Microbes by scientists at Japan's Advanced Institute of Science and Technology (JAIST), is one of the most striking pre-clinical results reported in cancer biology in recent memory.
Scientists at JAIST identified a naturally occurring bacterium from the intestines of Japanese tree frogs that demonstrated remarkable anticancer activity in mice, according to a ScienceDaily report published July 10, 2026 that brought renewed national attention to the research. The bacterium, Ewingella americana, was isolated from Dryophytes japonicus — the Japanese tree frog — and was found to be the most potent of 45 bacterial strains screened from the intestines of three amphibian and reptile species.
