This imbalance of beneficial versus harmful gut bacteria, called “dysbiosis,” causes a list of psychiatric and neurological disorders, including stress, autism, anxiety, and depression.

Moreover, it can even contribute to the development of neurodegenerative diseases, like Alzheimer’s and Parkinson’s disease. This might be a result of the pro-inflammatory states elicited by bacteria imbalance on or inside the body.

Additionally, researchers suspect that manipulating the gut bacteria can produce behaviors linked to anxiety and depression. A 2013 study showed that by replacing the gut bacteria of anxious mice with bacteria from fearless mice, mice became less anxious and more sociable. This also worked in reverse.

These findings are very important and promising, as the connection between the gut and brain can possibly be of help in the prevention and treatment of neurological and neuropsychiatric disorders.