Gut Bacteria Transplants Rejuvenate Adaptability of Aging Brains

In June 2026, researchers shared an exciting discovery about the connection between gut health and brain function. Scientists who worked in Italy have carried out experiments to see how bacteria affect brain plasticity.

Brain plasticity is the natural ability of the brain to change and learn new things. This ability is very high in childhood, but it decreases as we grow older.

In their first experiment, the team gave young mice high doses of antibiotics for ten days. This medicine caused significant changes in their gut microbiomes, which reduced the levels of helpful bacteria.

Specifically, the treatment reduced Lachnospiraceae, which are bacteria that produce healthy chemicals to protect nerve cells.

The researchers then covered one eye of each mouse for three days to test plasticity. They discovered that the brains of the treated mice did not adapt to this change.

By analyzing their genes, the scientists found that the antibiotics altered more than one thousand genes. These changes affected how nerves get wrapped in a protective sheath and changed the blood-brain barrier.

In order to reverse this process, they transplanted gut bacteria into older mice. The team used thirty-day-old donor mice to give young gut bacteria to four-month-old adult mice.

After performing the same eye-shutting test, they observed that the brains of these older mice became adaptable.

Experts who read the study, such as Harriët Schellekens, think these findings are very promising. She pointed out that we might target the microbiome to help people recover from brain injuries.

However, other experts warn that we cannot immediately apply these results to humans. Our brains are much more complex, and our daily diets have a strong effect on our microbiomes.