Probiotics for Gastrointestinal Symptoms and Quality of Life in Autism: A Placebo-Controlled Pilot Trial

Abstract

<b><i>Objective:</i></b> A randomized pilot trial of gastrointestinal (GI) symptoms targeting probiotic for quality of life in autism spectrum disorder (ASD). <b><i>Methods:</i></b> Thirteen children, 3-12 years of age with ASD, anxiety, and GI symptoms, were randomized into a probiotic crossover trial of 8 weeks each on VISBIOME and placebo separated by a 3-week washout. VISBIOME contains eight probiotic species, mostly <i>Lactobacillus</i> and <i>Bifidobacterium</i>. Primary outcome was the Pediatric Quality of Life Inventory (PedsQL) GI module. Secondary outcomes included gut microbiota analysis, the Parent-Rated Anxiety Scale for ASD (PRAS-ASD), and parent-selected target symptoms. A mixed analysis model was applied. <b><i>Results:</i></b> Thirteen children were randomized, with 10 completing the study (77% retention): 6 in probiotic/placebo sequence, 4 in placebo/probiotic sequence. Adherence to study treatment was 96%. There were no serious adverse events (AEs), and more nonserious AEs occurred with placebo than with probiotic, including those attributable to treatment. Only 6 of the 10 guessed the correct treatment at the end of week 8. Over the 19-week trial, each outcome improved from baseline and PedsQL correlated significantly with abundance of <i>Lactobacillus</i> without discernable changes to microbiota composition/diversity. Although probiotic showed more improvement than placebo, PedsQL and PRAS-ASD were not statistically significant, as expected at this sample size. PedsQL effect size was <i>d</i> = 0.49 by the general model and <i>d</i> = 0.79 by simple comparison of week 8 changes. A parent-selected target symptom showed significant improvement in GI complaints on probiotic compared with placebo (<i>p</i> = 0.02, <i>d</i> = 0.79). Probiotic effects carried over through the 3-week washout. <b><i>Conclusion:</i></b> The VISBIOME formulation was safe and suggested a health benefit in children with ASD and GI symptoms who retained <i>Lactobacillus</i>. The moderate effect size compared with placebo warrants a larger trial using a parallel-group design.