Quirks & Quarks

Animals can breathe through their butts and oxygen up the wazoo may work for humans too

The experiment was inspired by aquatic organisms that use their intestines for respiration in low-oxygen conditions.

Experiments in animals demonstrate that supplementary oxygen can be absorbed through the lower gut

Respiratory failure often means the lungs aren't capable of taking in enough oxygen. A new study suggests administering supplementary oxygen through the intestines may be possible. (Shutterstock / sbw18)

A new study has demonstrated the possibility that oxygen could be delivered to patients in respiratory failure through the gut rather than through the lungs. 

Several aquatic organisms have evolved unique intestinal breathing mechanisms to survive under low-oxygen conditions using organs other than lungs or gills. One of those is a freshwater fish found in Eurasia and Africa known as the loach. Loaches can breathe using their intestines, which means they take in oxygen through their anus and absorb it in their intestines.

It has been long debated whether mammals have similar capabilities. Inspired by the loach, in a new study, Takanori Takebe a professor from the Medical and Dental University of Japan and the Cincinnati Children's Hospital demonstrated that mice, rats and pigs can successfully take in oxygen as gas or in a special liquid form through their intestines. 

The loach is a freshwater fish that can absorb oxygen through its intestine. This ability inspired a study to test whether mammals can do the same. (De Agostini via Getty Images)

Intestinal breathing of liquid and gas 

Takebe invented an intestinal gas delivery system in order to introduce pure oxygen through the rectum of a mouse. With the system in place, oxygen reached the bloodstream through the intestines, and and 75 per cent of the mice survived 50 minutes of low oxygen conditions that would ordinarily have been fatal in a much shorter time.

Next Takebe used a oxygen delivery system, which was less invasive and disruptive to the gut than the delivery of oxygen gas. This system used liquid perfluorocarbon chemicals which can absorb and release hold large amounts of oxygen. In trials with mice, rats and pigs, the system also successfully delivered oxygen, and removed carbon dioxide through the intestines.

Takanori Tabebe's study found that rodents and pigs can 'breathe' through their intestines in low-oxygen conditions (Submitted by Takanori Takebe)

Takebe intends to start human trials in the next year, and hopes ultimately this approach may offer a new method to support critically ill patients with respiratory failure.


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