Dr. Takanori Takebe, of Cincinnati Hospital Medical Center in Ohio, is on a mission to find out if people can breathe through their butts. As a medical doctor and stem cell biologist, Takebe spends most of his time trying to develop lab-made livers to treat organ failure. His side quest to explore backside breathing began several years ago when his father caught pneumonia and had to be put on a ventilator. Shocked at how invasive it was, Takebe worried about how the procedure might affect his dad, who had already had part of one lung removed. Curious as to whether there was any other way to help patients get oxygen into the body without involving the lungs, he read about how animals get oxygen through their skin or guts. With his background in gastroenterology, Takebe knew that the human intestinal tract is rich in blood vessels, which is why enemas can deliver medicine to the bloodstream. He suspected that perhaps oxygen could pass from the intestines into the bloodstream, too. Takebe and his colleagues developed an enemalike treatment that sends a liquid called perfluorodecalin up the rectum. This liquid, which is already used in some medical procedures, can be loaded up with oxygen. As it releases that oxygen into the body, space in the liquid’s chemical structure opens to absorb “exhaled” carbon dioxide. In experiments with mice and pigs, enemas of the super oxygen-rich liquid helped the animals survive low-oxygen conditions. Now, the researchers have tested the safety of butt breathing in people. Most fared well, though bloating and mild stomach discomfort were common side effects. Future clinical trials will show whether an oxygen-loaded version of the liquid actually delivers oxygen to people’s bloodstreams. Takebe also envisions intestinal oxygen as a supplement to other types of breathing support or a short-term stopgap when other treatments aren’t available.
