As gene-editing technologies continue to improve, the field of cross-species organ transplants, or xenotransplantation, continues to grow. Shlomo Brody examines the approach of Jewish law toward the use of such technologies, particularly regarding the permissibility of implanting pig organs in humans.
Last month, doctors in Maryland completed the world’s first heart transplant using a heart that came from a genetically modified pig. This was a breakthrough because the donor pig had undergone gene editing to remove a specific type of sugar from its cells thought to be responsible for previous organ rejections in patients.
Pigs have been utilized [in such experiments] for a number of reasons: they are easy to breed and maintain (albeit with some environmental costs); they are available in wide numbers; they can be bred under pathogen-free conditions; and, most importantly, they are similar in anatomy and physiology to humans.
In the Bible, the pig is singled out because it has split hooves but does not chew its cud, thereby disqualifying it from being kosher food. “And the swine—although it has true hoofs, with the hoofs cleft through, it does not chew the cud: it is impure for you. You shall not eat of their flesh or touch their carcasses; they are impure for you” (Leviticus 11:7-8). Beyond the prohibition of eating pork, the sages also decreed that it is prohibited to raise pigs in Israel or around the world. Yet despite the prohibition of consuming pork as well as the general taboo around pigs, there was never a ritual prohibition against gaining benefit from pigs.