Pope Francis Is Fine, Totally Fine, With Human-Animal Chimeras

A controversial study on growing human organs inside pigs gets blessed by the Catholic Church. 

Franco Origlia/Getty Images

Growing human organs inside a pig body doesn’t exactly sound Catholic church-friendly, but Pope Francis has apparently given the thumbs up to Spanish scientists developing human-animal chimeras.

In an interview with Scientific American, Juan Carlos Izpisua Belmonte of the Salk Institute revealed that the Pope “very nicely said yes” to his team’s stem cell research, which is focused on figuring out how to coax human cells to form organs inside animal bodies.

If they succeed, it could open up a wealth of new options for solving the donor shortage for organ transplantation. In the United States, an average of 22 people die every day waiting for an organ. The Vatican’s surprising decision to support such ethically gray research seems to stem from its respect for human (over animal) life.

“So the Vatican is behind this research and has no problem based on the idea is to help humankind,” Belmonte said. “And in theory all that we will be doing is killing pigs.”

Here's a pig in a bucket.

Ben Salter (Flickr: Pig in a bucket) [CC BY 2.0 (], via Wikimedia Commons

The Pontifical Academy of Sciences — the Vatican’s science squad — hasn’t released any public statements confirming the Pope’s blessing, but if what Belmonte says is true, then Francis is officially more chill than the U.S. National Institutes of Health. Just last September, the NIH announced a controversial moratorium on funding research having to do with human chimeras.

This research is considered ethically murky because it’s one thing to harvest a pancreas grown from human stem cells from a pig, but what happens if those stem cells get into the pig’s brain? Or sperm? If a pig has a couple of human neurons floating around in its gray matter, do we have to treat it any differently? Should we worry about its chimera piglets? Until it can ponder these seemingly unanswerable ethical dilemmas, the science agency refuses to shell out any more cash to researchers working in the field.

The NIH hasn’t responded to urgent calls to reconsider the moratorium, which scientists argue is putting potentially life-saving research on hold. Belmonte’s work, though based in California, largely consists of collaborations with researchers in his (very Catholic) home country, Spain, which is likely how he’s been able to continue his work.

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