Science News reports on medical doctor and stem cell biologist Takanori Takebe’s quest to build a back-door alternative to invasive, awkward ventilator machines for pneumonia patients … by harnessing the gut’s ability to absorb oxygen almost as well as lungs do:
With his background in gastroenterology, Takebe knew that the human intestinal tract is rich in blood vessels. That’s why enemas can deliver medicine to the bloodstream. Takebe 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 this super oxygen-rich liquid helped the animals survive low-oxygen conditions. Each 400-milliliter dose boosted pigs’ blood oxygen levels for about 19 minutes at a time. Takebe’s team shared those findings in Med in 2021. Further pig tests reported in 2023 showed the technique could improve animals’ oxygen levels for up to half an hour.
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Now, the researchers have tested the safety of butt breathing in people. Twenty-seven healthy male volunteers in Japan each took a dose of non-oxygenated perfluorodecalin up the anus and were asked to hold it for an hour. Those smallest dose group got a squirt of 25 milliliters. The biggest dose was a whopping 1.5 liters — the maximum approved for “contrast agent” liquids used in X-ray scans of the GI tract.
Four of the six men in the planned 1.5-liter group had to stop receiving liquid early due to stomach pain. But most of those who got up to 1 liter fared pretty well, bloating and mild tummy discomfort aside, Takebe’s team reports in the Dec. 12 Med.
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You can read more of Takebe’s research here, in Cell: Med.