Abstract
BACKGROUND: In this double-blind placebo-controlled randomised intervention we investigated the potential benefits of a prebiotic supplement on children's well-being in a home setting. The primary aim was to determine if this supplement could effectively reduce anxiety, improve mood, and enhance cognitive function, similar to findings in young adults. METHODS: Fifty-three healthy children, aged 6 to 14, participated in an 8-week trial. The trial consisted of three testing time points; day zero marked the baseline measurement (T1) followed by a 28-day supplement intervention period during which they consumed 5.5 g of the prebiotic galactooligosaccharides (GOS) daily under parental guidance. Endline measures (T2) were conducted on the last day of supplement consumption, with a final follow-up testing session (T3) on day 56. Primary outcomes were trait anxiety using a questionnaire and emotional behavior in a dot-probe task on responses to positive and negative images. Secondary outcomes encompassed depression levels, cognitive function tests, and dietary intake recorded in a 4-day food diary. Additionally, we explored whether parents' emotional behavior had an impact on children's responses. RESULTS: While our statistical analysis did not reveal significant effects of GOS, there were noteworthy trends. Trait anxiety levels decreased over time in both groups, with a more pronounced decrease in the GOS group (after intervention, p =.090; after follow-up, p =.031). The GOS group exhibited reduced negative emotional responses compared to the placebo group (p =.105), and post-trial depression levels decreased in the GOS group over time (p =.015). Although parental emotional responses correlated with various emotional outcomes in children, they did not influence the intervention effects. CONCLUSIONS: These findings suggest positive trends in line with our hypotheses, however further investigation with greater statistical power would be beneficial. TRIAL REGISTRATION: Retrospectively registered on https://clinicaltrials.gov/ [NCT06258135] on February 6, 2024.