Anxiolytic effects of a galacto‐oligosaccharides probiotic in healthy females (18–25 years) with corresponding changes in gut bacterial composition.

The Publication

It is now widely accepted that the microbiota can directly affect our brain function and behaviour. The gut and the brain are connected via neural and endocrine pathways, known as the gut-brain axis. This relationship is presented in studies which show how changes in gut microbiota functioning have been linked to symptoms of anxiety and depression, and to social functioning in autism. Notably, gut microbiota variations during neurodevelopment may lead to dysfunctions in network maturation, causing atypical behaviour. It is therefore key to understand the role microbiota plays in brain function and plasticity.

Changes in diet can drastically change the microbial population in just a few days. Furthermore, the introduction of probiotics and prebiotics, also called ‘psychobiotics’, have been shown to improve gut microbial populations and subsequently to reduce symptoms of anxiety and depression. The present study investigated whether the  prebiotic, galacto‐oligosaccharide, GOS, influences gut microbiotic activity to affect anxiety and mood in late adolescence and early adulthood.

GOS reduced anxiety in those with high trait anxiety. This was correlated with increased activity of Bifidobacterium as a result of the GOS supplementation.

Our Response

This study highlights how supplementation with a prebiotic can change the activity of a microbial population and subsequently elicit anti-anxiety effects. This is another study demonstrating how nutrition and nutritional supplementation affect brain health. However, this study goes further and demonstrates one of the mechanisms by which this happens; showing the key role that microbes play in modulating mental health.