Researchers from scientific centers in the United States and Europe have demonstrated, through an experiment with mice published in the journal Nature, what the deterioration of the memory has its origin in the device digestive.
The finding reveals that Gastrointestinal aging and alterations in the microbiota activate an inflammatory response which impairs the connection between the intestine and the brain.
This process, led by myeloid cells, directly affects the vagus nerve, which explains why some individuals experience more rapid mental aging than others.
The biological pathway of cognitive aging
The investigation determined that The process begins with microbial and metabolic changes derived from the passage of time in the digestive tract. These alterations activate immune system cells in the intestine, causing inflammation that interrupts fluid communication with the brain.
To verify this relationship, the scientists carried out a coexistence experiment between young (two months) and old (18 months) mice. After a month of shared exposure to the microbiota, the young specimens developed a microbiome similar to that of the old and showed deficiencies in tests of object recognition and maze resolution, levels of deterioration previously seen only in elderly specimens.
The role of bacteria Parabacteroides goldsteinii
The study identifies a specific agent in this process: the bacteria Parabacteroides goldsteinii. According to the authors, the presence of this microorganism increases with age, generating the inflammation necessary to deactivate the functions of the vagus nerve.
The experts found that, by deliberately colonizing the intestines of young mice with this bacteria, their cognitive abilities decreased. In contrast, mice raised in germ-free environments showed significantly slower mental decline, which reinforces the thesis that specific components of the microbiome drive memory loss.
Possibility of reversing cognitive damage
One of the most optimistic findings of the study is the reversibility of this deterioration. By restoring the young mice’s original microbiota using antibiotics, they regained their youthful levels of cognitive function.
Likewise, the team led by Christoph Thaiss, from the Arc Research Institute of California, found that restoring the activity of the vagus nerve in elderly mice allows recovery of memory function.
Since stimulation of this nerve is already approved in humans to treat conditions such as epilepsy, The researchers hope that these findings can soon be translated into clinical practice to combat age-related cognitive decline in people.