Could a fecal microbiota transplant (FMT) delay or even reverse aging?
As you grow older, the diversity of the gut microbiota and the number of species present increases. In adulthood, the gut microbiota structure and composition remain constant but then gut microbiota deteriorates in aged individuals. Centenarians have different gut microbiota, studies have shown that centenarians have an abundance of Verrucomicrobia, Christensenellaceae, and Bifidobacterium. It has been suggested that the presence of these specific bacteria may be the reason why centenarians have enhanced lifespans (even though researchers are not sure why this is).
FMT is whereby fecal filtrate from a healthy donor is transplanted into an individual that has dysfunctional gut microbiota. Apparently; FMT can restore healthy gut microbiota in the recipient and thus FMT may be applied to the field of longevity. Bárcena and colleagues found that FMT in two progeroid mice models had prevented progression of the aging phenotype which is commonly seen in the progeroid diseases, and FMT also improved the lifespan of the progeroid mice.
It would be interesting to see whether FMT has geroprotective capabilities in aged mice and even aged humans in the future.
Lynch, Susan V., and Oluf Pedersen. "The human intestinal microbiome in health and disease." New England Journal of Medicine 375.24 (2016): 2369-2379.
Biagi, Elena, et al. "Gut microbiota and extreme longevity." Current Biology 26.11 (2016): 1480-1485.
Bárcena, Clea, et al. "Healthspan and lifespan extension by fecal microbiota transplantation into progeroid mice." Nature medicine 25.8 (2019): 1234-1242.