RESUMO
BACKGROUND: This study was designed to examine the possible efficacy of the probiotic strain Lactobacillus acidophilus LB (Lacteol Fort) on attention-deficit/hyperactivity disorder (ADHD) symptomatology and evaluate its influence on cognition function. METHODS: In this randomized controlled trial, 80 children and adolescents with ADHD diagnosis, aged 6-16 years, were included. The participants were randomly assigned to two groups: one group received probiotics plus atomoxetine, whereas the other group received atomoxetine only. ADHD symptomatology was assessed using the Conners Parent Rating Scale-Revised Long Version (CPRS-R-L) and Child Behavioral Checklist (CBCL/6-18). The participants were evaluated for their vigilance and executive function using Conner's Continuous Performance Test (CPT) and Wisconsin Card Sort Test (WCST). Both groups were assessed at the beginning of the study and the end of the twelve weeks. RESULTS: The probiotic group comprised 36 patients, whereas the control group comprised 40 patients in the final analysis after four patients dropped out of the trial. After 3 months of probiotic supplementation, a significant improvement in the CPRS-R-L and CBCL total T scores was observed compared with those in the control group (p = 0.032, 0.024, respectively). Additionally, the probiotic group demonstrated improved focus attention (target accuracy rate and omission errors;p = 0.02, 0.043, respectively) compared with the control group. An analysis of the Wisconsin Card Sorting Test (WCST) performance demonstrated that the probiotic group had significantly lower perseverative (p = 0.017) and non-perseverative errors (p = 0.044) but no significant differences compared to the control group. CONCLUSION: Lactobacillus acidophilus LB supplementation combined with atomoxetine for 3 months had a beneficial impact on ADHD symptomology and a favorable influence on cognitive performance. As a result, the efficacy of probiotics as an adjunctive treatment for managing ADHD may be promising. TRIAL REGISTRATION: ClinicalTrials.gov (identifier: NCT04167995). Registration date: 19-11-2019.