Effects of Probiotic Supplementationon Gastrointestinal, Sensory and Core Symptoms in Autism Spectrum Disorders: A Randomized Controlled Trial

The microbiota-gut-brain axis has been recently recognized as a key modulator ofneuropsychiatric health. In this framework, probiotics (recently named "psychobiotics")may modulate brain activity and function, possibly improving the behavioral profiles ofchildren with Autism Spectrum Disorder (ASD). We evaluated the effects of probiotics onautism in a double-blind randomized, placebo-controlled trial of 85 preschoolers with ASD(mean age, 4.2 years; 84% boys). Participants were randomly assigned to probiotics (DeSimone Formulation) (n=42) or placebo (n=43) for six months. Sixty-three (74%) childrencompleted the trial. No differences between groups were detected on the primaryoutcome measure, the Total Autism Diagnostic Observation Schedule - CalibratedSeverity Score (ADOS-CSS). An exploratory secondary analysis on subgroups ofchildren with or without Gastrointestinal Symptoms (GI group, n= 30; NGI group, n=55)revealed in the NGI group treated with probiotics a significant decline in ADOS scores ascompared to that in the placebo group, with a mean reduction of 0.81 in Total ADOS CSSand of 1.14 in Social-Affect ADOS CSS over six months. In the GI group treated withprobiotics we found greater improvements in some GI symptoms, adaptive functioning,and sensory profiles than in the GI group treated with placebo. These results suggestpotentially positive effects of probiotics on core autism symptoms in a subset of ASDchildren independent of the specific intermediation of the probiotic effect on GI symptoms.Further studies are warranted to replicate and extend these promising findings on a widerpopulation with subsets of ASD patients which share targets of intervention on themicrobiota-gut-brain axis.