Scientists confirm breathing through our bottoms is safe after first human trial

Just when you thought science had advanced far enough, you get another surprise, this time in the form of the first successful completion of a human trial of enteral ventilation or, well, breathing through our bottoms – sort of.

As it happens, researchers have for the first time carried out a successful experiment on humans of the method that delivers oxygen through the rectum using an oxygen-carrying liquid, showing the procedure is safe and well tolerated, according to a study published in the journal Med on October 20.

The science behind the ‘backdoor’ to breathing

Specifically, enteral ventilation works by administering a liquid called perfluorodecalin (PFD) through the rectum, where oxygen can then be absorbed into the intestinal wall and transferred to the bloodstream – a process inspired by aquatic species like loaches, which breathe through their intestines in oxygen-poor water.

In the words of organoid medicine expert Takanori Takebe from the University of Osaka and Cincinnati Children’s Hospital, who led the study, the technique proves a backdoor “to provide partial oxygen support while allowing the lungs to rest,” highlighting that:

“Enteral ventilation is not meant to replace mechanical ventilators or ECMO [Extracorporeal Membrane Oxygenation], but rather to serve as a complementary oxygenation route.”

During the Phase I safety study, 27 healthy male volunteers received up to 1 liter of perfluorodecalin rectally, but without oxygen added, since the aim was only to test for safety. None of the participants experienced serious side effects, with the most common symptoms being mild bloating or temporary discomfort.

The team now plans a Phase II trial using oxygenated perfluorodecalin (O₂-PFD) in patients suffering from hypoxemia and other forms of respiratory failure. If proven effective, the therapy could help premature infants, ARDS patients, or those with acute respiratory distress when other ventilation methods are not possible.

Although it might sound bizarre, the scientific community has recognized the approach for its ingenuity and Takebe’s team received the 2024 Ig Nobel prize, which honors “achievements that first make people laugh, and then make them think,” in an experience that Takebe referred to as a “reminder that truly unconventional ideas often being at the boundary between curiosity and skepticism.”