In the experiment, six-month-old male mice were divided into two groups: one group received a standard diet, while the other was fed a high-salt diet consisting of 8% sodium chloride. After six months, the mice consuming the salty food exhibited symptoms of increased blood pressure, anxious behavior, and memory deterioration.
During behavioral tests, the mice on the salty diet showed avoidance of open spaces and performed worse in recognizing new objects. Examination of their brains revealed a decrease in neuron density in the hippocampus, which is responsible for learning and memory.
The researchers also noted changes in genetic activity: there was increased expression of inflammatory genes in the hippocampus, while genes that promote cell survival were suppressed. This indicates a possible development of neuroinflammatory processes.
Concurrently, an analysis of the gut microbiome composition showed significant changes: on a high-salt diet, the proportion of certain bacteria increased, while the number of beneficial microorganisms decreased. These changes were linked to inflammatory processes in the brain.
The authors of the study conclude that an excess of salt can alter the gut microbiome, and the byproducts of bacterial activity or immune signals may negatively affect the brain, leading to changes in gene function and neuron death.
According to recommendations from the World Health Organization, the maximum salt intake should be five grams per day; however, experts estimate that most people significantly exceed this limit, consuming twice as much.
