Microbiome Depletion Rejuvenates The Aging Brain
Our bodies are home to trillions of tiny microorganisms, collectively known as the microbiome, with a significant population residing in our gut. While often beneficial, new research suggests that changes in this gut community as we age might actually contribute to the brain’s decline.
A recent study explored what happens when the gut microbiome of older mice is significantly reduced, essentially clearing out many of these resident microbes. The results were quite remarkable: the brains of these mice showed signs of rejuvenation. For instance, the density of tiny blood vessels in the brain, crucial for delivering nutrients and oxygen, improved. The protective coating around nerve fibers, called myelin, which helps nerve signals travel efficiently, also showed enhancements. Furthermore, the creation of new brain cells, a process known as neurogenesis, increased, and the activity of immune cells in the brain, called microglia, which can become overactive and harmful with age, was reduced.
These physical improvements translated into better brain function, as the mice demonstrated improved memory. Researchers also observed changes at a genetic level, indicating a widespread shift in how various brain cells were operating. Importantly, they found a decrease in substances that promote inflammation, including a specific signaling molecule called eotaxin-1. Interestingly, simply blocking eotaxin-1 on its own could reverse some aspects of brain aging.
This work suggests that the aging gut microbiome might shift towards a more inflammatory state, negatively impacting brain health. While this research was conducted in mice, it opens up exciting possibilities for developing new ways to promote brain health and resilience in humans by carefully targeting the gut microbiome or its related biological signals.
Source: link to paper