Poop Transplant Reverses Brain Aging in Mice, Restoring Youthful Function

June 19, 2026 - 19:35

A surprising new study has found that older mice given faecal transplants from younger donors showed remarkable improvements in brain function. Their brains became more plastic, meaning they could adapt and learn more like young animals. This allowed them to overcome a neurological condition that usually only responds to treatment in childhood.

The research focused on a specific type of brain plasticity that is critical for learning and memory. In young mice, this plasticity is high. In old mice, it drops off sharply. After receiving the faecal transplant, the older mice regained a level of brain flexibility that let them recover from a condition that mimics a common human developmental disorder. Normally, this condition can only be fixed if treated early in life. The old mice, after the transplant, showed recovery that was previously thought impossible at their age.

Scientists believe the gut microbiome plays a powerful role in brain health. The bacteria in the younger mice's guts likely produced compounds that traveled to the brain, reducing inflammation and supporting the regrowth of protective myelin sheaths around nerve cells. This allowed the old brains to rewire themselves. The findings suggest that targeting the gut microbiome could one day lead to new treatments for age-related cognitive decline or developmental disorders in humans. However, researchers caution that human trials are still a long way off, and the exact mechanisms need further study. For now, the results offer a striking example of how the health of the gut can directly influence the aging brain.