The technique sounds so outlandish that it won an IgNobel prize in 2024. But the science behind rescuing people with blocked airways and clogged lungs by rectally delivering oxygen to the body is no joke.
In fact, positive results were published Oct. 20, 2025 , in the journal Med regarding the first human clinical trial to evaluate the potential benefits of "enteral ventilation."
"This is the first human data, and the results are limited solely to demonstrating the safety of the procedure and not its effectiveness. But now that we have established tolerance, the next step will be to evaluate how effective the process is for delivering oxygen to the bloodstream," says Takanori Takebe, MD, PhD, a leading expert in organoid medicine with dual appointments at Cincinnati Children's and the University of Osaka in Japan.
What is enteral ventilation?
This concept envisions an enema-like process that uses a super-oxygenated liquid to deliver life-supporting oxygen to the bloodstream by absorbing it through the colon.
A key paper detailing initial findings in a porcine model was featured on the cover of Med in 2021 and later in the popular Canada-based science television show, "The Nature of Things." That early work led to Takebe and colleagues receiving an IgNobel Prize in 2024 .
If successful in ongoing human trials, the relatively low-tech process may allow hospitals to rescue people when airways are blocked by injury or inflammation, or when lung function is severely limited by infections and other complications.
A new idea with decades-old roots
The inspiration for the procedure comes in part from observing the abilities of the loach, a bottom-feeding fish that can swallow air from the surface and absorb the oxygen through its gut, thus supplementing its gills to survive in low-oxygen conditions.
It also builds upon the work of former Cincinnati Children's researcher Leland Clark, PhD, (b.1918, d.2005) who years ago invented a perfluorocarbon liquid, now called Oxycyte . Although the product did not move forward as a potential form of artificial blood, the 1989 movie "The Abyss" included a famous scene in which a rat was shown "breathing" the special liquid.
Findings and next steps
The new study recaps findings from 27 healthy men in Japan who were asked to hold varying amounts of the perfluorocarbon liquid (without the liquid being oxygenated) for 60 minutes.
Twenty held the liquid for the entire 60 minutes, including amounts up to 1,500 ml. At the largest volumes, participants reported abdominal bloating and discomfort, but no serious adverse events were reported.
A key next step will be to repeat the evaluation using the oxygenated liquid to measure how much of the liquid is needed, and for how long, to improve blood oxygen levels. Eventually, Takebe and colleagues hope to expand the technology for use in newborn care.
Takebe – who has launched a company called EVA Therapeutics to pursue this project – says the timing of a future clinical trial will depend on the pace of fundraising.
