An April 2021 study by the University of Surrey said,
"This new research marks a significant step forward in that we were able to show that we can use a simple and safe food supplement such as prebiotics to improve both the abundance of beneficial gut bacteria in the gut and to improve mental health and wellbeing in young women."
"This is an exciting study that brings together different dimensions in mental health research; finding prebiotic effects in a sub-clinical group shows promise for translational clinical research on multiple markers of mental health."
Some examples of prebiotic foods
Barley
Oats
Apples
Cocoa
Flaxseed
Garlic
Onions
Bananas
Wheat Bran
Seaweed
Burdock Root
Chicory Root
Dandelion Greens
Asparagus
Leeks