The future of anti-aging treatment could be found in feces

What’s your secret?
What’s your secret?
Image: AP Photo/Marcio Jose Sanchez
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The centuries-long search for a fountain of youth has led many people down regrettable holes. But maybe not this time.

A group of scientists, led by Dario Valenzano at the Max Planck Institute for Biology of Ageing, have found that older fish live longer when fed microbes from the feces of young fish. Their study hints at the role that the microbiome, a collection of microbes that live in and on the bodies of animals—including humans—may play in how we age.

Valenzano’s team used the killfish, whose lifespan is just a few months, as a test subject. They took middle-aged killfish, about nine weeks old, and killed the microbes in their gut with antibiotics. Next, they introduced the feces of young killfish, about six weeks old, into the tank. Though killfish aren’t known to eat feces, the microbes from the younger fishes’ feces did make their way into the sterile older fishes’ gut, researchers established by probing their gut contents.

Compared to normal killfish, those that let microbes from the younger fishes’ feces populate their guts had a 37% longer median lifespan. In a reverse experiment, where sterilized young killfish were fed the feces of middle-aged counterparts, there was no change in the lifespan.

Valenzano’s team doesn’t yet know the exact mechanism through which middle-aged fish are gaining longer lives. One possible explanation is the aging immune system may have let harmful bacteria beat beneficial ones. A gut transplant could’ve got rid of the build up of such harmful bacteria.

The study hasn’t yet been published in a peer-reviewed journal, but if its result stand scrutiny then the implications aren’t limited to fish. Scientists have previously found that the gut microbiomes of aging humans is less diverse than that of the young. Researchers in Canada, reports Nature, are already looking to study what a similar intervention does to aging mice. If the mice study is successful, it won’t be long before human clinical trials start.

Poo transplants might seem like an unappealing youth potion, but it’s not the only use for it. Previous human clinical trials have found fecal transplants can help treat infections, such as colitis, which even some of the best antibiotics struggle to overcome. Others are exploring whether “poo pills” can be used to treat malnutrition and obesity.