Randomized Double-Blind Crossover Study for Evaluating a Probiotic Mixture on Gastrointestinal and Behavioral Symptoms of Autistic Children

Abstract

Autism spectrum disorders (ASDs) represent a diagnostic challenge with a still partially uncertain etiology, in which genetic and environmental factors have now been assessed. Among the hypotheses underlying the involvement of biological and environmental factors, the gut–brain axis is of particular interest in autism spectrum disorders. Several studies have highlighted the related incidence of particular gastrointestinal symptoms (GISs) in children suffering from ASDs. Probiotics have shown success in treating several gastrointestinal dysbiotic disorders; therefore, it is plausible to investigate whether they can alleviate behavioral symptoms as well. On these bases, a randomized double-blind crossover study with a placebo was conducted, evaluating the effects of a mixture of probiotics in a group of 61 subjects aged between 24 months and 16 years old with a diagnosis of ASD. Behavioral evaluation was performed through the administration of a questionnaire including a Parenting Stress Index (PSI) test and the Vineland Adaptive Behavior Scale (VABS). The Psycho-Educational Profile and the Autism Spectrum Rating Scale (ASRS) were also evaluated. Microbial composition analyses of fecal samples of the two groups was also performed. The study showed significant improvements in GISs, communication skills, maladaptive behaviors, and perceived parental stress level after the administration of probiotics. Microbiome alpha diversity was comparable between treatment arms and no significant differences were found, although beta diversity results were significantly different in the treatment group between T0 and T1 time points. Streptococcus thermophilus, Bifidobacterium longum, Limosilactobacillus fermentum, and Ligilactobacillus salivarius species were identified as some of the most discriminant taxa positively associated with T1 samples. This preliminary study corroborates the relationship between intestinal microbiota and ASD recently described in the literature.

Symbiosis in the microbiome of people with asd and its effects on the brain-intestine linkage

“…perceived), with the administration of these specific probiotics: Streptococcus thermophilus, Bifidobacterium longum, Limosilactobacillus fermentum and Ligilactobacillus salivarius. The presence of these taxa related to the cited species was present in fecal samples, indicating intestinal colonization by probiotics in these patients (Guidetti et al, 2022).…”

Interconnection between Microbiota–Gut–Brain Axis and Autism Spectrum Disorder Comparing Therapeutic Options: A Scoping Review

“…Although clinical trial findings are limited, they urge additional investigation into FMT in ASD. This scoping review found that probiotic, prebiotic, synbiotic, FMT, or MTT supplementation improved different domains of ATEC score, including sociability, sensory or cognitive awareness, speech/communication/language, and health/physical/behavior, and there were improvements in behavioral symptoms in other studies that used different questionnaires (not ATEC) [ 29 , 45 , 46 , 47 , 48 , 50 , 52 , 54 , 55 , 57 , 58 ]. Concerning GI symptoms, all of the included trials found that probiotic, prebiotic, or symbiotic treatment improved the frequency of bowel movement-associated pain, diarrhea, constipation, and stool frequency [ 45 ].…”

“…Bifidobacteria levels appear to be inversely associated via feedback interactions with Desulfovibrio and Clostridium , two of the most likely bacteria strains involved in ASD etiopathogenesis [ 84 ]. In this vein, our analysis suggests that when baseline counts are aberrant, enhancing Bifidobacterial populations (MTT, B-GOS ® supplementation) or reducing Desulfovibrio and Clostridium growth rates might be viable targets in microbiota-based ASD therapy [ 46 , 47 , 48 , 49 , 50 , 51 , 52 ]. It is critical to understand which gut commensals are associated with better symptoms in order to generate next-generation probiotics (also known as live biotherapeutic products) that evolve the features required to complete within the GI tract of ASD patients [ 85 ].…”

Physical Activity, Gut Microbiota, and Genetic Background for Children and Adolescents with Autism Spectrum Disorder

“…Although no significant differences were observed in microbiome alpha diversity among groups, beta diversity in children with ASD were significantly different between start and at 3 months compared to those without ASD. There were some taxa that were positively associated with the three-month samples, such as Bifidobacterium longum , Streptococcus thermophilus , Limosilactobacillus fermentum , and Ligilactobacillus salivarius [ 162 ].…”