Anxiolytic effects of a galacto-oligosaccharides prebiotic in healthy female volunteers are associated with reduced negative bias and the gut bacterial composition

Current research implicates pre- and probiotic supplementation as potential mediators for improving symptomology in numerous physical and emotional ailments. The alteration of emotional states via nutrient intake is an attractive concept for clinicians and consumers alike and may be an efficient channel to improved well-being. Here we focus on the period of late adolescence, which is a time of emotional refinement via maturation that significantly influences emotional, social and physical well-being in later years. Effective interventions such as nutritional supplementation in this age group have the potential to offset health-related costs in later life. In this study we examined multiple indices of mood and well-being in 64 healthy females in late adolescence in a 4-week double blind, placebo controlled Galacto-oligosaccharide (GOS) prebiotic supplement intervention. We also obtained stool samples at baseline and follow-up for microbiome sequencing and analyses. We found effects of the GOS intervention on sub-clinical self-reported high trait anxiety, attentional bias, and bacterial abundance, suggesting that dietary supplementation with a GOS prebiotic may be influential in improving indices of pre-clinical anxiety.