Age-related loss of cognitive ability causes intestinal microbiota

Scientists in Britain and Italy have found that transplanting faecal microbiota from old mouse to young mouse leads to learning and memory difficulties for young people. This discovery further supports a growing body of evidence linking age-related cognitive decline to changes in the intestinal microbiota.

Scientists have already discovered a number of intriguing relationships between the intestinal microbiota and the brain. Depression, memory, even character traits somehow relate to the bacteria in the intestines. However, the nature of the relationship between the microbiota and the brain is still unexplored. Science knows that changes in the brain lead to changes in the microbiota. For example, a stroke in the brain of a mouse causes a change in a population of bacteria in the intestinal tract. There is also data on the movement of metabolites from the intestine to the brain, which leads to an aggravation of neurovascular diseases.

In a new study, a three-month-old mouse was first given antibiotics to destroy the intestinal microbiota, and then faecal microbiota was transplanted from mouse at 24 months of age (close to the limit). After that, the scientists conducted a series of tests on metabolism, behavior and cognitive abilities, writes New Atlas.

No changes in behavior, motor activity or level of anxiety were observed. However, mouse showed signs of impaired memory and spatial learning.

The scientists also noted that fecal transplantation changed the expression of proteins associated with synaptic plasticity and neutrontransmission in the hippocampus. Previous studies have shown that age-related learning and memory impairments may be associated with hippocampus deficits.

It is still unclear whether fecal back grafting of young mouse will restore the cognitive functions of old mouse.