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Did a Frog-Gut Bacterium 'Completely Eradicate Cancer' and Beat Chemo? What the Study Shows
An Instagram post says one dose of a Japanese tree frog gut bacterium wiped out cancer in 100% of mice and outperformed chemotherapy and immunotherapy. The study is real. It was done in mice, in one type of colon tumor.
Original commentary from the Cancer Explained editorial team.
Please note: this page is educational only — it is not medical advice, and it does not speculate about anyone’s health beyond reliable public reporting. For questions about your own health, talk with your healthcare team.
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An Instagram Reel from @nic.hulscher, posted around October 10, 2026, says a bacterium found in the gut of a Japanese tree frog "completely eradicated cancer in 100% of treated mice after one dose." It says the bacterium, Ewingella americana, "outperformed chemotherapy and immunotherapy."
We have covered this study before: see our first look and our check of an earlier Reel. This page looks at the new claim that it beat chemotherapy and immunotherapy.
What's real
The study exists. It was published in the journal Gut Microbes in 2025 by a team at the Japan Advanced Institute of Science and Technology (JAIST). The authors are Iwata, Yamasita, Asukabe, Sakari and Miyako. The team grew 45 bacterial strains from the intestines of Japanese tree frogs, fire-bellied newts and grass lizards. Nine strains showed some anti-tumor effect. E. americana worked best.
Press coverage of the paper says one intravenous dose cleared tumors in every treated mouse in a colorectal cancer model. It also says the mice were protected when cancer cells were injected again 30 days later. Those reports also say the bacteria left the bloodstream within about 24 hours and were not found in normal organs. Mild inflammation passed within 72 hours. Mice were followed for 60 days.
What's missing or wrong
- "Cancer" is really one mouse tumor model. The reports describe a mouse model of colorectal cancer. That is not all cancer, and it is not human cancer.
- "Outperformed chemo and immunotherapy" is a mouse comparison. Reports say the bacterium did better than an immune checkpoint inhibitor and liposomal doxorubicin in these mice. We could not open the full paper, so we cannot tell you the dose, timing or group sizes behind that comparison. Beating a drug in mice does not show it would beat that drug in people.
- "100%" can sound bigger than it is. Animal studies like this often use small groups. An earlier article of ours, citing the paper, put the rechallenge group at 10 cured mice. We could not confirm group sizes in the full paper this time.
- It is an injected live bacterium. Safety in mice over 60 days does not tell us what happens in people, especially people with weakened immune systems.
- Nothing here is a treatment. No person has been reported to have received it. We found no announced human trial.
What the evidence says
Animal results are an early step. Many treatments that clear tumors in mice do not work the same way in people. Human testing happens in stages, described in clinical trial phases. Researchers in this paper called the work early-stage. Other coverage says more cancer types and combinations need testing before any move to people.
Using bacteria against tumors is a real research field. But a mouse result is a reason to keep studying, not a reason to change care.
What to do with this
Treat the post as "interesting early lab news," not "cancer cured." Do not try to find, make or take bacteria from animals. Injecting live bacteria outside a trial could cause serious infection. If you are in treatment, do not change or skip it because of a social media post. Ask your care team about it, and about clinical trials that might fit you. See how to recognize cancer misinformation online.
If you are in treatment and have a fever of 100.4 F (38 C) or higher, call your care team right away. For an emergency, call 911.
Sources
- Iwata S, Yamasita N, Asukabe K, Sakari M, Miyako E. "Discovery and characterization of antitumor gut microbiota from amphibians and reptiles: Ewingella americana as a novel therapeutic agent with dual cytotoxic and immunomodulatory properties." Gut Microbes 2025; 17(1): doi.org/10.1080/19490976.2025.2599562. The publisher page and the PMC copy (PMC12710904) would not open for us. We read the abstract through Europe PMC.
- ScienceDaily, July 2026 coverage of the study: sciencedaily.com
- The Microbiologist, "Gut Bacteria from Amphibians and Reptiles Achieve Complete Tumor Elimination": the-microbiologist.com
- National Cancer Institute, "Immunotherapy to Treat Cancer": cancer.gov
How this article was prepared
An AI-assisted editorial system helped prepare this page. It used the paper's abstract and press coverage of the study. We could not open the full paper, so details on group sizes, funding and the chemotherapy comparison are not confirmed here. No named medical reviewer has reviewed it unless one is listed.
Cancer Explained is published by the National Cancer Information Foundation. It is not medical advice and does not suggest a test or treatment.
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Put the story in context
Prevention, possible warning signs, screening, and diagnosis
This story relates to colorectal cancer. The information below is general: it does not reveal anything else about a public person’s health, and not every point applies to every cancer. Personal advice depends on age, symptoms, family history, exposures, and medical history.
Prevention and risk reduction
Not every cancer can be prevented. Avoiding tobacco, protecting skin from ultraviolet radiation, limiting alcohol, staying active, and receiving recommended HPV or hepatitis B vaccination can lower the risk of certain cancers. A risk factor is not a prediction or a cause in one individual.
Symptoms and possible early signs
Possible signs vary and are often caused by conditions other than cancer. Changes worth discussing include a new lump, unexplained bleeding or weight loss, a persistent cough, lasting bowel or bladder changes, a changing skin spot, or symptoms that persist or worsen. Some early cancers cause no symptoms.
Screening and early detection
Screening looks for certain cancers before symptoms begin. Recommended tests exist only for some cancers and depend on age and risk. Screening can have benefits and harms; it is not the same as evaluating a new symptom, and there is no single routine scan or blood test that reliably screens for every cancer.
How cancer is diagnosed
Diagnosis may involve a history and exam, imaging, laboratory tests, and often a biopsy. Pathology can identify the cancer type and may test biomarkers that guide treatment. Symptoms, screening results, tumor markers, or online stories alone cannot confirm cancer.
Learn about this story’s cancer topic
A public story may encourage questions, but it should not be used to estimate your risk or choose testing. Contact a healthcare professional about a persistent or concerning change. Seek urgent care for severe or rapidly worsening symptoms.