Could poop be the secret to “eternal youth?” It’s perhaps not quite as ridiculous (or gross) as it might sound.
As reported in the journal Nature Aging, a new study has shown how transplanting gut microbiota from young to old mice helped reverse some aging-associated changes in the brain.
Scientists from APC Microbiome Ireland (APC) at the University College Cork carried out the fecal transplants, transferring bacteria from the gut, between either a young mouse (aged 3 to 4 months) or an old mouse (19 to 20 months) to an old mouse.
The aging mice that received the gut bacteria of the young mice were found to express biomarkers, including metabolites and patterns of gene regulation, that you’d expect to see in younger mice. On top of this, fecal transplants from young mice improved the behavior of older mice, allowing the oldies to perform better in several cognitive tests that measure learning ability, memory, and anxiety. However, the transplants from old mice to equally old mice did not have any significant effect.
The gut microbiome is the bustling ecosystem of trillions of bacteria, viruses, archaea, and fungi that live in the digestive tracts of humans and other animals. Recent research suggests that “foreign” microbes and human cells are present in comparable numbers in the human body. In terms of genetic material, the human body is home to more bacteria genes than human genes.
For each and everyone one of us, this complex system of microorganisms is deeply entwined with the brain and body, playing a fundamental role in our metabolism, immune system, brain function, and perhaps even our personalities. The gut microbiome remains relatively stable through adulthood, but it will change and become less diverse in old age. It also appears that changes in our gut microbiome might predict how well we age.
According to the authors, the findings suggest that manipulating the trillions of microorganisms that live in the gut could potentially be a way to ward off and even reverse aging-associated cognitive decline. For now, this has only been shown in mice, but the team hopes the promising results could pave the way towards further research in humans.
"Previous research published by the APC and other groups internationally has shown that the gut microbiome plays a key role in aging and the aging process. This new research is a potential game-changer, as we have established that the microbiome can be harnessed to reverse age-related brain deterioration. We also see evidence of improved learning ability and cognitive function," Professor John F Cryan, study author and principal Investigator at APC said in a statement, though he cautioned, "it is still early days and much more work is needed to see how these findings could be translated in humans."
Not that people will necessarily want to experience fecal transplants to keep the brain young and healthy. These findings could pave the way for future emphasis on the gut from a dietary perspective to keep the brain and body healthy.