Scientists from the University of Louisville and the University of Texas have found out that there are intestinal bacteria that affect the death of brain cells and cognitive decline.
We are talking about the IAA metabolite, it is produced by the family of intestinal bacteria Ruminococcaceae. It affects the death of nerve cells, which leads to a decrease in cognitive abilities.
The team decided to conduct an experiment to understand how this metabolite affects brain function. The authors took old mice and found that with age, the number of Ruminococcaceae bacteria and the IAA metabolite in the body increases.
The metabolite itself binds to the promoter region of the S100A8 gene, then the gene expression occurs, and then the formation of apoptotic bodies and the death of nerve cells.
To find out the consequences of getting IAA into the brain, the authors orally administered a drug containing this metabolite to young healthy mice and observed the reaction.
As a result of several behavioral and cognitive tests, it turned out that the effects of IaaS led to a loss of cognitive function: rodents began to learn worse how to navigate in a maze and recognize objects. The opposite effect was observed when scientists blocked the action of IA on microglia in elderly mice: this provoked an improvement in memory and spatial learning.