Effect of multispecies probiotics on autism symptoms: protocol for a randomized controlled trial (PROBAUT).

Researchers are planning a study to test whether probiotics (beneficial bacteria) can help reduce autism symptoms in children. The study will give 110 children aged 7-15 either probiotics or a placebo for 12 weeks. They will measure changes in autism symptoms, quality of life, sleep, family stress, and stomach problems. This study protocol describes how they plan to test whether improving gut bacteria might help with autism symptoms.

This is a protocol for PROBAUT, a randomized controlled trial investigating multispecies probiotic supplementation for autism symptoms. The study will recruit 110 children aged 7-15 with autism spectrum disorder for a 12-week intervention comparing probiotics versus placebo. The probiotic mixture contains eight bacterial strains. Primary outcome measures core autism symptoms using the Autism Symptom Rating Scales, with secondary outcomes including quality of life, sleep, parental stress, gastrointestinal symptoms, and urinary biomarkers.

This represents a well-designed protocol addressing the gut-brain connection in autism through microbiome modulation. The study is registered and ethically approved, indicating rigorous methodology for investigating probiotics as a therapeutic approach for autism spectrum disorder.

This protocol represents important research into gut-brain connections in autism. The comprehensive outcome measures and rigorous methodology suggest potential for generating meaningful evidence about probiotic interventions. However, no clinical recommendations can be made until trial results are available.

This is a protocol paper describing planned research, not results. No efficacy data is available yet. The study results are pending completion of the trial.

Autism spectrum disorder (ASD) affects millions of children worldwide, negatively impacting the daily functioning and quality of life of patients and their families. New therapeutic approaches for ASD are being investigated. Probiotics have shown promise in modulating gut microbiota and ameliorating ASD symptoms. We aim to evaluate the impact of a 12-week multispecies probiotic supplementation on the severity of core autism symptoms in children with ASD.

This study is a randomized, double-blind, placebo-controlled clinical trial. One hundred and 10 children aged 7 to 15 years diagnosed with ASD will be randomly assigned in a 1:1 ratio to receive either a probiotic mixture or a placebo for 12 weeks. The probiotic mixture contains 5 × 10colony-forming units per dose of Bacillus subtilis W20, Bifidobacterium infantis W17, Bifidobacterium lactis W51, Lactobacillus acidophilus W37, Levilactobacillus brevis W63, Lacticaseibacillus rhamnosus W140, Lactococcus lactis W19, and Propionibacterium freudenreichii W200. The primary outcome will be the assessment of core autism symptoms using the Autism Symptom Rating Scales (ASRS).

The secondary outcomes will include the quality of life, evaluations of sleep impairments, parental stress levels, gastrointestinal symptoms, and urinary p-cresol levels. These outcomes will be assessed twice: at baseline and after 12 weeks of intervention. The study has received approval from the Ethics Committee of the Medical University of Warsaw. Results will be submitted to a peer-reviewed journal and presented at national and international scientific meetings.

NCT06448767. Registered on 3 June 2024 Protocol version Version 2, 27 of October 2025.