Gut Microbiome Linked to Fear Response
Fear is a normal emotion that allows an individual to perceive and deal with an impending threat. Fear is hard-wired into us and controlled by the amygdala.
Understanding how fear and fear-associated memories are controlled is a significant step necessary for the development of therapies for conditions such as post-traumatic stress disorder and certain phobias. The relatively recent discovery of the gut-brain axis has tantalizingly revealed that the bacteria in our intestines (the gut microbiome) have the capacity to alter stress and anxiety-related behaviors.
Now scientists at the APC Microbiome Institute at University College Cork, have discovered that the microbiome regulates fear responses. They believe that their discovery will lead to new treatments for a range of anxiety disorders.
The research team used germ-free mice (never exposed to bacteria) to test the role of the microbiome in fear. They found that mice with no microbiome were less afraid than mice that grew up with an intact microbiome.
At the molecular level, they discovered that the amygdala (the emotional processing center of the brain) was hyperactive in the germ-free mice, which shows that the gut microbiome is necessary for a normal fear response.
The research team is actively seeking to develop new microbiome-focused therapies as a treatment for anxiety disorders. One potential approach to this could be a new psychobiotic, a probiotic with mood-altering effects.