Previous studies have shown a direct correlation between gut microbes and the central nervous system. Using a zebrafish model, researchers determined that a common probiotic sold in supplements and yogurt can decrease stress-related behavior and anxiety.

See the source article by following the link below:
Previous studies have shown a direct correlation between gut microbes and the central nervous system. Using a zebrafish model, researchers determined that a common probiotic sold in supplements and yogurt can decrease stress-related behavior and anxiety.