memes

Quite the contrary...

first, it has a natural affinity for the low-oxygen environment inside solid tumors, so within just 24 hours it had increased its numbers by around 3,000-fold, but it also didn't drift over to impact any other healthy organs or tissue. Then it's able to directly kill the growth thanks to toxins it secretes inside the tumor.

At the same time, the bacterial invasion triggered a natural immune response, and the tumors soon became flooded with immune cells – particularly neutrophils, and T and B cells – alongside increases in inflammatory signaling molecules. The combined effect was widespread tumor cell death driven both by direct bacterial action from the foreign gut bug and by the host’s own immune system.

...

Importantly, this mechanism appears to also be highly tumor-specific, with E. americana sticking only to the tumor environment. The researchers believe this selectivity arises from a combination of factors unique to tumors – insufficient oxygen (hypoxia), leaky blood vessels, altered metabolism and locally suppressed immune defenses that allow the bacterial colony to thrive where they are also most destructive.