| The Neuroscience of the Gut 2025-08-30 science papers > The microbe-free animals were more active and, in specific behavioral tests, were less anxious than microbe-colonized mice. > They found that colonizing an adult germ-free animal with normal gut bacteria had no effect on their behavior. However, if germ free animals were colonized early in life, these effects could be reversed. This suggests that there is a critical period in the development of the brain when the bacteria are influential. |