We generally don’t like to think about the fact that there is a large worm-like organ inside of our abdomens. That’s the sort of thing which you usually only have to make peace with when watching horror comedies like Slither, but it doesn’t stop it from being true. Your intestines stretch for roughly 15 feet inside your body, winding a path between your stomach and rectum.
Despite being among the creepiest of your internal organs, your intestines play a crucial role in your everyday life, taking up nutrients from the food you eat and ridding your body of waste, but their job ends at your end. They can’t, for instance, help you breathe right?
Getting the oxygen needed for survival is achieved through various processes in the animal kingdom. Insects gather oxygen through holes in in their bodies known as spiracles, and some vertebrate animals can breathe through their butts. Sort of.
In the winter, turtles slow their metabolism and get most of their oxygen through their cloaca in a process known as cloacal respiration. Other reptiles and amphibians use similar respiration techniques to breathe without using lungs. If you happen to be a mammal, however, it’s long been believed that if your lungs are out of commission than you are out of luck. At least until recently.
We’ve long known that the intestines could take up chemical components and deliver them to the rest of the body. That’s one of the ways your gut microbiome communicates with your brain, but it was unclear if the same or similar processes could be used to get oxygen into the blood stream.
To test the hypothesis, scientists created a scenario in which pigs and mice in a laboratory were deprived of normal respiration and ventilated via the intestines. To improve the likelihood of oxygen uptake, some animals had their intestines scrubbed in order to thin the mucosal lining and reduce the barrier to the blood stream. Their findings were published in the journal Clinical and Translational Resource and Technology Insights.
Unsurprisingly, control animals who were deprived of respiration and received no intestinal ventilation, died after about 11 minutes. Animals who received intestinal ventilation without the intestinal scrubbing survived almost twice as long, about 18 minutes, indicating that there was some oxygen uptake. Lastly, 75% of those animals who had been scrubbed and received pressurized oxygen into the rectum, survived for an hour, the total length of the experiment.
This seemed to prove that mice and pigs are capable of intestinal respiration under the right conditions, giving researchers reason to believe that other mammals — like humans — might have the same capability.
However, the process of scrubbing the intestines is potentially dangerous and researchers wanted to uncover if there was an alternative solution which could achieve similar results. Their answer turned out to be oxygen-rich liquids known as perfluorocarbons. They repeated a similar experiment, again using mice and pigs, but this time they flooded the intestines which perfluorocarbons instead of gaseous oxygen. They found that the animals experienced increased blood oxygen levels which measured at normal levels.
While the effect has not yet been tested on humans, scientists suggest it might serve as an effective alternative respiration technique when conventional methods like mechanical ventilation don’t work. It’s also possible that introducing high levels of oxygen into the digestive tract will have a negative impact on the microbiome, but that’s generally a secondary concern if you can’t breathe. Further testing is needed to determine if intestinal ventilation might be an effective lifesaving tool in people.
With any luck, most of us won’t ever been in a situation where we’ll need intestinal ventilation. However, if a respiratory disease knocks us on our butts and our lungs are bottoming out, we might be willing to consider a little derri-air.