Note: Single-source report; awaiting corroboration.
NIH-funded researchers examined how aging affects gut-brain communication in mice, focusing on microbiome changes. Older mice showed reduced memory performance compared to younger mice. When gut bacteria in young mice were altered to resemble those of older mice, their memory also declined. This was achieved by housing young and old mice together or transplanting gut bacteria from old to young mice. Antibiotic treatments that depleted gut bacteria in both groups improved cognitive performance, suggesting a key role for microbiomes in memory function.
The study found that the bacterium Parabacteroides goldsteinii increased significantly with age in mice. Exposure to this bacterium negatively impacted cognitive tests. Its associated fatty acids triggered inflammation in myeloid cells, a type of white blood cell. This inflammation impaired signaling from the gut to the brain via the vagus nerve, affecting gut-brain communication. These findings suggest a possible mechanism linking gut microbiota changes to age-related memory loss.
The research, published in Nature, may guide future efforts to develop treatments aimed at preventing or reversing age-related cognitive decline in humans, pending further studies.