Take a look at the Figure 2 of https://www.tandfonline.com/doi/full/10.1080/19490976.2025.2... It's a live mouse, they inject a tiny amount of cancer cells, wait line a week until they replicate and fro to 200mm3[1], and then inject the bacteria and wait like another week, and the cancer dissapears. All of this while the mouse is alive.
"mouse model" is standard name. It means that is somewhat a model of a human.
[1] Cubic units are too hart to visualize, if it were a perfect sphere, the diameter would be 7mm ~= 1/4 inch.
Mouse models in papers like these mean they're using (live) mice to model human systems. They may even be altered or genetically engineered mice, which present problems of their own: for example Alzheimer's treatment candidates which work in mice that have been changed to have "Alzheimer's-like symptoms" rarely produce the same results in humans with actual Alzheimer's. But yes, in general an animal model is a cohort of live animals used to get a sense for what the effect would be like in humans.
The study was in real, living mice. From the study text:
> The experimental design employed clinically relevant dosing regimens: E. americana was administered as a single intravenous injection via tail vein at a dose of 200 μL (5 × 10⁹ CFU/mL), while anti-PD-L1 and DOX were administered intravenously every other day for four total injections at 2.5 mg/kg, representing standard therapeutic protocols.
Not the GP, but I'll bite. I'm skeptical too, so I read TFA.
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They tried 9 bacterias and a 1 control group. Using n=3 * (9+1) = 30 mice they got this result:
> Most remarkably, E. americana demonstrated exceptional therapeutic efficacy, achieving potent tumor suppression and complete tumor regression (complete response, CR) following a single bacterial administration. The therapeutic kinetics revealed that mice treated with R. qingshengii exhibited initial tumor suppression up to day 5 post-injection; however, tumor re-growth was subsequently observed, suggesting that while this strain possesses antitumor activity, its therapeutic effects are not sustained long-term.
They claim "p < 0.0001" that in my opinion is a loooot of zeros for only 3 mice.
They end the experiment after 40 days, so it's not clear if the cancer would reappear after a a few months.
They tried again with 5 mice, and got similar results, so it doesn't look like a fluke, but it's a very short time to claim an "elimination" line in the title of the press release. The research article has a more neutral tone.
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It looks like the idea is that these bacterias can survive without oxygen, so they are happy to live in the tumor that usually has a low number of capilar and blood and oxygen. IIUC the bacterias kill the nearby tumor cells, perhaps steal their food and also make the immune system go there and kill everything just in case. This sounds like a sensible idea, but it's too far from my area to be sure.
Fwiw, 3 mice is imho sufficient because these mice might as well be clones. They're not clones, but they're genetically very similar to one another, so variations in results are not expected.
It sounds something that could easily be tested aside from regulatory issues. Just find some terminal cancer patients and inject some E. americana.
Or maybe try it on cats/dogs etc. if they don't want to risk curing humans.
They did it in a "mouse model" does that mean it wasn't even a live mouse?
[I'm skeptical as always, anyway...]
Take a look at the Figure 2 of https://www.tandfonline.com/doi/full/10.1080/19490976.2025.2... It's a live mouse, they inject a tiny amount of cancer cells, wait line a week until they replicate and fro to 200mm3[1], and then inject the bacteria and wait like another week, and the cancer dissapears. All of this while the mouse is alive.
"mouse model" is standard name. It means that is somewhat a model of a human.
[1] Cubic units are too hart to visualize, if it were a perfect sphere, the diameter would be 7mm ~= 1/4 inch.
Mouse models in papers like these mean they're using (live) mice to model human systems. They may even be altered or genetically engineered mice, which present problems of their own: for example Alzheimer's treatment candidates which work in mice that have been changed to have "Alzheimer's-like symptoms" rarely produce the same results in humans with actual Alzheimer's. But yes, in general an animal model is a cohort of live animals used to get a sense for what the effect would be like in humans.
Genetically altered mice were NOT used in the study.
The study was in real, living mice. From the study text:
> The experimental design employed clinically relevant dosing regimens: E. americana was administered as a single intravenous injection via tail vein at a dose of 200 μL (5 × 10⁹ CFU/mL), while anti-PD-L1 and DOX were administered intravenously every other day for four total injections at 2.5 mg/kg, representing standard therapeutic protocols.
Gut bacteria cure cancer. Ladies and gentlemen, the peak HN health/med post.
Injecting a bacteria from a frog is absolutely bizarre. But gut bacteria having a major role in cancer risk is nothing new.
Better eat your reptiles.
Fortunately, the study is from Japan, where Gojira gut sushi was already in high demand.
Yum, Gojira
in mice
Sounds too good to be true. I don't buy this. Every once in a while (several times a year) I bump in an article claiming to cure cancer.
Being outright dismissive without a corresponding article-specific argument is about the worst thing you can ever do on any forum.
This is not to be confused with dismissing with an article-specific argument (which you don't have).
Not the GP, but I'll bite. I'm skeptical too, so I read TFA.
---
They tried 9 bacterias and a 1 control group. Using n=3 * (9+1) = 30 mice they got this result:
> Most remarkably, E. americana demonstrated exceptional therapeutic efficacy, achieving potent tumor suppression and complete tumor regression (complete response, CR) following a single bacterial administration. The therapeutic kinetics revealed that mice treated with R. qingshengii exhibited initial tumor suppression up to day 5 post-injection; however, tumor re-growth was subsequently observed, suggesting that while this strain possesses antitumor activity, its therapeutic effects are not sustained long-term.
They claim "p < 0.0001" that in my opinion is a loooot of zeros for only 3 mice.
They end the experiment after 40 days, so it's not clear if the cancer would reappear after a a few months.
They tried again with 5 mice, and got similar results, so it doesn't look like a fluke, but it's a very short time to claim an "elimination" line in the title of the press release. The research article has a more neutral tone.
---
It looks like the idea is that these bacterias can survive without oxygen, so they are happy to live in the tumor that usually has a low number of capilar and blood and oxygen. IIUC the bacterias kill the nearby tumor cells, perhaps steal their food and also make the immune system go there and kill everything just in case. This sounds like a sensible idea, but it's too far from my area to be sure.
Fwiw, 3 mice is imho sufficient because these mice might as well be clones. They're not clones, but they're genetically very similar to one another, so variations in results are not expected.
Granted, the other concerns hold.