An international team of researchers has found that fecal transplants could one day be used to restore cognitive function and quality of life in the elderly.
"Research has shown that the aging process may be linked with age-related changes in our gut microbiota. Recently, the existence of two-way communication between the gut and the brain—known as the 'gut-brain axis' – has emerged as an important player in shaping aspects of behavior and cognitive function," says Dr. David Vauzour, one of the study's authors. "We wanted to see whether transferring gut microbes from older to younger mice could affect parts of the central nervous system associated with aging."
For their study, the researchers transferred fecal matter from older mice to young adult mice. They then assessed the younger mice's microbial profiles as well as their behavior, particularly looking for markers including anxiety, exploratory behavior, and memory.
In the end, they found that the younger mice showed no significant changes in anxiety levels, explorative behavior, or locomotor activity. Significantly, however, the researchers noticed that they performed worse in a maze test that measured for spatial learning and memory.
These cognitive changes corresponded both with significant differences in their microbial profiles as well as differences in protein expression linked to synaptic plasticity and neurotransmission. The researchers also noticed differences in the cells in their hippocampus- the part of the brain responsible for learning and memory.
"While it remains to be seen whether transplantation from very young donors can restore cognitive function in aged recipients, the findings demonstrate that age-related shifts in the gut microbiome can alter components of the central nervous system." says professor Claudio Nicoletti, one of the study's authors.
As such, the researchers say that their findings highlight the importance of the gut-brain axis in aging, and thus support further development of therapies that restore young-like microbiota to improve cognitive function in the elderly.