In an emergency, mammals can absorb oxygen through the intestines.
This is the result of a study published in the journal "Med" by scientists from Tokyo Medical and Dental University.
According to the researchers, this finding could benefit humans.
In the event of a lack of ventilators, as is currently the case in some countries due to the corona pandemic, patients could possibly be ventilated rectally.
It was already known that certain fish such as loaches and catfish, but also sea cucumbers and orb web spiders can breathe with their intestines.
The Japanese researchers around Ryo Okabe now investigated for the study published on Friday whether the same applies to mice, rats and pigs under experimental conditions.
To do this, they first reduced the oxygen supply to the test animals and introduced the oxygen into their intestines in gaseous form.
To stimulate blood circulation and improve oxygen uptake, they previously caused inflammation in the intestinal mucosa.
Since this procedure would be difficult for humans, they introduced oxygen to the test animals in a second experiment using the liquid chemical substance perflunafen.
In both cases, the behavior of the animals normalized through rectal ventilation and they survived the oxygen deprivation longer.
According to the scientists, the intestinal bacteria were not negatively affected.
The scientists now hope to be able to test their method in human clinical trials.
"In patients with shortness of breath, this method can support oxygenation to reduce the negative effects of oxygen deprivation while treating the underlying condition," said co-author Takanori Takebe.
"This is a provocative idea and those who first hear about it will be amazed," wrote Caleb Kelly of the Yale School of Medicine in an accompanying commentary on the study. But it is "a very promising therapy" that could play a role in the case of a lack of ventilators, as is currently the case in the corona pandemic.