Not long ago, researchers reported that pigs and mice—and presumably humans—could absorb oxygen through the membranes lining their rectums (https://scitechdaily.com/no-joke-pigs-and-rodents-can-breathe-through-their-butts/). The key was a liquid (perfluorocarbon) that can hold large amounts of dissolved oxygen. It is supplied to the rectum via enema.
Perfluorocarbons have been under development for years as synthetic blood substitutes (https://www.phlbi.org/divisions/blood-disorders/artificial-blood/). They are nontoxic and can be stored for use on battlefields and in trauma wards, but problems have prevented approval. Because those problems only arise when the perfluorocarbons are administered intravenously, administration via enema is considered likely to be safe. Indeed, researchers are planning clinical trials in pursuit of approval for use in humans with impaired lung function, such as Covid-19 patients in the ICU (http://www.asahi.com/ajw/articles/14350603?fbclid=IwAR0NQH27VJvP3iEE5EqjC0hOtzHkgROJDpvy_q5idn7eoJu2Sv-YfXcXgVQ). If everything works out, we will have a new tool for helping hard-hit patients.
There are other potential applications as well. One factor that limits sports performance is the ability to deliver oxygen to the muscles. Athletes work to improve this ability by training at high altitude, where the air contains less oxygen. The body responds by building up the quantity of oxygen-carrying red blood cells in the blood. The same thing can be accomplished by taking the hormone erythropoietin, but that is considered “doping” and banned (https://www.wada-ama.org/en/questions-answers/epo-detection). Oxygen can, however, be administered after a race to aid recovery. At present, “To be able to breathe air with increased oxygen during exercise, special equipment such as tanks, bottles, or aggregates with facial masks are required. However, in connection with most athletic competitions, technical accessories cannot be carried or used” (https://onlinelibrary.wiley.com/doi/full/10.1111/sms.12746).
Sports authorities have said nothing about using pre-competition high-oxygen perfluorocarbon enemas to increase oxygen availability to the blood. Therefore, at present, they are legal.
Would they work? Would they enhance performance? Would they make runners and cyclists fleeter? Swimmers swifter? We do not yet know.
But someone will surely try it before long. Perhaps the popular enema brand Fleet will see a marketing opportunity. Perhaps sponsors will be putting their logos on the butt-plugs that hold the enema in. (Unless those are ruled to be illegal “technical accessories.”)
Shortly after that, of course, sports authorities will start debating whether this is a form of doping. Shortly after that, high-oxygen perfluorocarbon enemas will be banned in sports.
They will, however, still be usable for activities such as high-altitude mountain climbing. The military may find them useful in combat. Perhaps students would use them before exams.
The future is a very strange place.
