A new study of mice, published in online research journal Nature Aging, has shown that transplanting gut bugs from young to old mice can counteract ageing-related changes in the brain, suggesting that ‘poo’ transplants could one day help ageing brains beat cognitive decline.
The researchers from University College Cork in Ireland collected the faecal matter from young mice and introduced it to the gut of old recipient mice and found that it reversed age-related changes in the immune system of the old mice.
The brains of old mice receiving poo transplants from mice were also rejuvenated and they improved in several cognitive tests for learning, memory and anxiety.
The findings suggest that transplants may have therapeutic potential for the treatment of ageing-associated cognitive decline.
Microorganisms that live on and in the human body have an impact on health and vary with age.
‘Friendly’ bacteria — which have beneficial effects on the metabolic and immune systems — can be gradually replaced with bacteria that drive chronic inflammation, metabolic dysfunction and disease.
Microorganisms in the gut shape local immunity, but can also affect brain aging and increase the risk of neurodegenerative diseases.
John Cryan, Marcus Boehme and colleagues transplanted faecal microbes from the gut of either young (3-4 months) or old (19-20 months) donor mice into old recipient mice (19-20 months).
The team found that aging-associated changes in the immune system of the old mice were reversed by the transfer of gut microbiota from the young mice.
The brains of old mice receiving young donor-derived faecal transplants were also rejuvenated and contained metabolites and patterns of gene regulation that resembled the brains of the younger mice.
Furthermore, faecal transplants from young mice improved the behaviour of older mice in several cognitive tests for learning, memory and anxiety.
The authors conclude that these findings reveal the potential of the gut microbiome as a therapeutic target for the promotion of healthy aging.
Future research is needed to explore how specific bacteria or their metabolites within the microbiome may be responsible for these effects.
Nature Aging is a new online-only research journal publishing research from across the entire spectrum of the aging-research community, ranging from the basic biology of aging to the impact of aging on society.