Japanese study confirms safety of rectal oxygen carrier in healthy volunteers, opening doors for future respiratory failure treatments.
A viral post on X by @thatuglyblogger last week caught widespread attention, claiming scientists had conducted the first “butt-breathing” trial on humans to deliver oxygen through the rectum. The post, which included images explaining the concept, described enteral ventilation as a way to aid patients with lung issues. Based on peer-reviewed research and corroborating reports, this account holds up as accurate, marking a real step in experimental medicine.
A tweet from X.
The concept dates back to animal studies where pigs, loaches, and turtles can absorb oxygen through their intestines when their lungs are unable to do so. Scientists from Cincinnati Children’s Hospital Medical Center, led by Dr. Takanori Takebe, advanced the concept by carrying out studies in pigs, for which they received a 2024 Ig Nobel Prize-a award for work that’s both unusual and thought-provoking. Those studies demonstrated that rectal oxygen can sustain life in airway blockages, and it reduces the need for mechanical ventilators that sometimes lead to further injury to the lungs. The main ingredient used is perfluorodecalin (PFD), a synthetic liquid that carries considerably more oxygen than water does, serving as a carrier for the diffusion of gas across the gut lining into the bloodstream.
In the trial published Oct. 20, 2025, in the journal Med, researchers administered non-oxygenated PFD to 27 healthy Japanese men aged 20-45 in doses ranging from 25 to 1,500 milliliters, delivered rectally and retained for 60 minutes. No serious adverse events occurred participants described only minor bloating or discomfort that quickly passed. Seven couldn’t finish the full hour due to unease, but vital signs stayed normal, and blood tests showed no PFD absorption. Funded by EVA Therapeutics, where a senior author holds inventor status, the study focused solely on safety not on proving oxygen delivery works. Plans include efficacy tests in patients with conditions like acute respiratory distress syndrome (ARDS), where ventilators fall short.
Public views often lean toward humor, with “butt-breathing” sparking jokes online, yet the ethical side involves careful human translation from animal data. Trials prioritized consent and minimal risk, addressing dignity concerns in critical care. As Dr. Takebe stated in a New Atlas interview,
“this could revolutionize critical care if we can prove it works in sick patients.”
The authors conclude:
“intrarectal PFD is feasible and appears tolerable, establishing a safety base for follow-up studies.”
This development underscores how offbeat ideas, once dismissed, can spark genuine progress. In an era of ventilator shortages seen during COVID-19, such innovations merit serious pursuit, though full validation lies ahead. For more, see the full study at pubmed.ncbi.
