Clinical and metabolic reaction to probiotic supplement in children suffering attention-deficit hyperactivity disorder: A randomized, double-blind, placebo-controlled experiment

Aim: This paper aimed at assessing the influence that probiotic supplement had on mental health and metabolic conditions of children suffering attention-deficit hyperactivity disorder (ADHD). Materials and Methods: A number of 34 children with ADHD were selected randomly. Participants were randomly allocated into a group receiving 8 × 109 CFU/g probiotic supplements (n = 17) and a group receiving placebo (n = 17) during an 8-week time period. Clinical symptoms were recorded applying the rating scale of ADHD (ADHD-RS), Children's Depression Inventory (CDI), and Hamilton Anxiety Rating Scale (HAM-A) both at onset of the study and after the 8-week interval. Moreover, samples of blood were also taken at the beginning and after the 8-week interval so that the metabolic information could be evaluated. Results: The probiotic supplementation could bring about a considerable decrease in total ADHD-RS (β −3.31; 95% confidence interval [CI]: −5.60, −1.02; P = 0.006) and HAM-A (β −1.91 [0.18]; 95% CI, −3.41, −0.41; P = 0.01) than that of the placebo. In addition, probiotic supplementation brought about a considerable decrease in high sensitivity C-reactive protein (hs-CRP) of serum (β −2.05 mg/L; 95% CI, −3.57, −0.52; P = 0.01) as well as a substantial rise in plasma overall antioxidant volume (TAC) (β 66.26 mmol/L; 95% CI, 36.83, 95.68; P < 0.001) than that of the placebo. No meaningful effects were observed on CDI and other metabolic features after the intake of probiotic supplements. Conclusions: Taking probiotic by children suffering ADHD could affect ADHD-RS, HAM-A, hs-CRP of serum, and TAC levels in plasma, while it did not show any effects on CDI and other metabolic profiles.