An Explanation From the Scientist Behind That Cat Poop Cancer Treatment
In a scientific discovery at Dartmouth recently hailed as “highly shareable” by the internet, cat poop is being mentioned in connection with a newly discovered potential cancer treatment.
Toxoplasma gondii, a single-celled parasite found in the guts of cats, has been used in a lab to treat cancer. It might, after enough testing turn out to be a viable cancer therapy. However, toxoplasma is a strange, shape-shifting organism, and the kind cats poop out won’t shrink your tumors one bit. Still, Dartmouth recently publicized the very promising discovery: A modified version of toxoplasma, when injected into mice with certain kinds of cancer, switched on an immune response that the cancer had deactivated, which then allowed the body to fight the disease itself.
David J. Bzik, Ph.D. of Dartmouth’s Geisel Medical School has been experimenting with toxoplasma for at least a decade. He says the discovery that an altered form of the parasite might cure cancer is a big deal, but that toxoplama is weird and wonderful microbe that still has surprises in store for humanity, none of which involved ingesting cat poop by any stretch of the imagination.
He also schooled me on some interesting trivia I thought I knew about toxoplasma. What follows is an edited version of my conversation with him.
I’m reading a lot of headlines about cat poop curing cancer. Oh of course. They’re sensationalist.
What should they be reporting? We developed this strain of toxoplasma that doesn’t replicate.
Could you remind us what toxoplasma is? It’s a protozoan. Its closest relative is malaria, it’s in the same phylum.
And what happens when it can’t reproduce? It doesn’t cause disease in mice. It’s a great vaccine for toxoplasmosis [which], in AIDS patients is a really big disease. Also in cancer patients, when their immune systems are suppressed, they’re vulnerable to natural infections by toxoplasma. So having a vaccine is a good idea. This has not been tested as a vaccine yet in humans or cats, and we also haven’t tested the anti-cancer effects in humans either. This has all been mouse work.
Cats in the United States release about 2.6 billion pounds (1.2 million metric tons) of feces into the environment every year. Cat dung carries the parasite Toxoplasma gondii, a single-celled organism that creates infectious agents called oocysts. These oocysts can infect pregnant women, causing congenital problems in the baby such as deafness, seizures, eye damage and mental retardation. The parasite also infects people with compromised immune systems, such as those with HIV/AIDS.
After reviewing past studies on the parasite, a team of researchers believes the Toxoplasma parasite may be a significant public health problem, infecting people who are otherwise healthy. Other studies have even linked the parasite to schizophrenia, depression, suicidal behavior and lower school achievement in children.
Cats — those gif-able, meme-driving, better-than-dog pets — are awesome. Their poop? Not so much.
It’s long been known that some cats carry a parasite called Toxoplasma gondii, or T. gondii, and that they shed an embryonic form of the parasite, called oocysts, in their feces. When transferred to humans, the parasite can cause a disease known as toxoplasmosis, which results in flu-like symptoms and muscle pains that can last for a month or longer.