TOKYO, Japan — When most people think of a breathing, it’s safe to say they picture taking air in through the nose and letting it out through the mouth (or nose again). Could the future of respiratory health mean taking a deep breath in and letting it out through your backside? A new study finds some mammals are able to breathe through their bottoms, with scientists adding rodents and pigs to that list. According to their findings, you may be able to add humans to the list of species using their intestines to breathe in the future.
If this is the case, intestinal ventilation systems, which pumps oxygen through the rectum, could save millions of people worldwide from respiratory failure, a team from Japan says. This is especially important when factoring in the demand for ventilators during the coronavirus pandemic.
Is ‘back-to-front breathing’ possible?
Certain aquatic organisms practice the “back-to-front breathing” to survive in places with low levels of oxygen. For example, sea cucumbers and fresh water fish (including loaches and catfish) can use their rear end instead of their lungs or gills to breathe. However, whether mammals have the same ability has been “heavily debated,” until now.
“Artificial respiratory support plays a vital role in the clinical management of respiratory failure due to severe illnesses such as pneumonia or acute respiratory distress syndrome,” says study author Dr. Takanori Takebe from Tokyo Medical and Dental University in a media release.
“Although the side effects and safety need to be thoroughly evaluated in humans, our approach may offer a new paradigm to support critically ill patients with respiratory failure.”
The researchers developed a gas ventilation system to administer pure oxygen through animals’ rectums and tested it on mice, rats, and pigs. Results show, without the system, no mouse survived more than 11 minutes in extremely low oxygen conditions.
With ventilation on the other hand, 75 percent of mice survived for 50 minutes in the same normally lethal conditions. Unfortunately the system required breaking the animals’ intestinal barrier and so was not clinically feasible for humans, especially in severely ill patients.
Finding new ways to breathe during COVID
To remedy this, the researchers developed a liquid-based alternative ventilator. It uses chemicals, oxygenated perfluorochemicals, which are biologically compatible and safe in humans. Researchers tested the new system on rodents and pigs exposed to low but non-lethal levels of oxygen. Both mice and pigs receiving ventilation received more oxygen and could walk faster in a chamber with 10 percent oxygen. Study authors note it also added more color to the animals’ skin and helped keep them warm.
“Taken together, the results show that this strategy is effective in providing oxygen that reaches circulation and alleviates respiratory failure symptoms in two mammalian model systems,” Dr. Takebe reports.
Finding new ways of treating respiratory failure has become increasingly important during COVID-19. Next, the researchers plan on expanding their pre-clinical studies and taking regulatory steps towards bringing their system to market.
“The recent SARS-CoV-2 pandemic is overwhelming the clinical need for ventilators and artificial lungs, resulting in a critical shortage of available devices, and endangering patients’ lives worldwide,” Dr. Takebe concludes.
“The level of arterial oxygenation provided by our ventilation system, if scaled for human application, is likely sufficient to treat patients with severe respiratory failure, potentially providing life-saving oxygenation.”
The findings appear in the journal Med.
SWNS writer Tom Campbell contributed to this report.