20/06/2025
Gut Brain connection is real and affected by vagus nerve
A new study shows how the gut microbiome, the bacteria living in our gut, can send signals to the brain through the vagus nerve. Scientists used mice without any gut bacteria, known as germ-free mice, and found that their vagus nerve activity was much lower than in normal mice. But when they gave these germ-free mice normal gut bacteria, the vagus nerve activity returned to normal.
The researchers also tested what happens when antibiotics are used to kill the bacteria in normal mice. When this happened, the vagus nerve activity dropped. However, when they gave these mice fluids from the intestines of normal mice, the vagus nerve activity went back up. This didn't happen when they used fluids from germ-free mice, proving that gut bacteria are important.
The scientists also found that certain substances made by gut bacteria, like short-chain fatty acids and bile acids, play a key role in sending signals through the vagus nerve. These substances activate specific neurons in the nerve, which send messages to the brainstem. This shows that the gut microbiome can communicate directly with the brain, which could help us understand more about how our gut affects our brain and lead to better treatments for brain and gut problems.
