Saccharomyces boulardii: potential adjunctive treatment for children with autism and diarrhea

Interplay Between Peripheral and Central Inflammation in Autism Spectrum Disorders: Possible Nutritional and Therapeutic Strategies

Pre- and post-natal factors can affect brain development and function, impacting health outcomes with particular relevance to neurodevelopmental diseases, such as autism spectrum disorders (ASDs). Maternal obesity and its associated complications have been related to the increased risk of ASDs in offspring. Indeed, animals exposed to maternal obesity or high fat diets are prone to social communication impairment and repetitive behavior, the hallmarks of autism. During development, fatty acids and sugars, as well as satiety hormones, like insulin and leptin, and inflammatory factors related to obesity-induced low grade inflammation, could play a role in the impairment of neuroendocrine system and brain neuronal circuits regulating behavior in offspring. On the other side, post-natal factors, such as mode of delivery, stress, diet, or antibiotic treatment are associated to a modification of gut microbiota composition, perturbing microbiota-gut-brain axis. Indeed, the interplay between the gastrointestinal tract and the central nervous system not only occurs through neural, hormonal, and immune pathways, but also through microbe-derived metabolic products. The modification of unhealthy perinatal and postnatal environment, manipulation of gut microbiota, nutritional, and dietary interventions could represent possible strategies in preventing or limiting ASDs, through targeting inflammatory process and gut microbiota.

The microbiota-gut-brain axis and its potential therapeutic role in autism spectrum disorder

Autism spectrum disorder (ASD) is a series of neurodevelopmental disorders that are characterized by deficits in both social and cognitive functions. Although the exact etiology and pathology of ASD remain unclear, a disorder of the microbiota-gut-brain axis is emerging as a prominent factor in the generation of autistic behaviors. Clinical studies have shown that gastrointestinal symptoms and compositional changes in the gut microbiota frequently accompany cerebral disorders in patients with ASD. A disturbance in the gut microbiota, which is usually induced by a bacterial infection or chronic antibiotic exposure, has been implicated as a potential contributor to ASD. The bidirectional microbiota-gut-brain axis acts mainly through neuroendocrine, neuroimmune, and autonomic nervous mechanisms. Application of modulators of the microbiota-gut-brain axis, such as probiotics, helminthes and certain special diets, may be a promising strategy for the treatment of ASD. This review mainly discusses the salient observations of the disruptions of the microbiota-gut-brain axis in the pathogenesis of ASD and reveals its potential therapeutic role in autistic deficits.

Microbiome Disturbances and Autism Spectrum Disorders

Autism spectrum disorders (ASDs) are considered a heterogenous set of neurobehavioral diseases, with the rates of diagnosis dramatically increasing in the past few decades. As genetics alone does not explain the underlying cause in many cases, attention has turned to environmental factors as potential etiological agents. Gastrointestinal disorders are a common comorbidity in ASD patients. It was thus hypothesized that a gut-brain link may account for some autistic cases. With the characterization of the human microbiome, this concept has been expanded to include the microbiota-gut-brain axis. There are mounting reports in animal models and human epidemiologic studies linking disruptive alterations in the gut microbiota or dysbiosis and ASD symptomology. In this review, we will explore the current evidence that gut dysbiosis in animal models and ASD patients correlates with disease risk and severity. The studies to date have surveyed how gut microbiome changes may affect these neurobehavioral disorders. However, we harbor other microbiomes in the body that might impact brain function. We will consider microbial colonies residing in the oral cavity, vagina, and the most recently discovered one in the placenta. Based on the premise that gut microbiota alterations may be causative agents in ASD, several therapeutic options have been tested, such as diet modulations, prebiotics, probiotics, synbiotics, postbiotics, antibiotics, fecal transplantation, and activated charcoal. The potential benefits of these therapies will be considered. Finally, the possible mechanisms by which changes in the gut bacterial communities may result in ASD and related neurobehavioral disorders will be examined.

Complementary and alternative medicine treatments for children with autism spectrum disorders

There are many treatments in current use for core and associated symptoms of autism spectrum disorders (ASD). This review discusses the complementary and alternative medical (CAM) treatments commonly added to conventional interventions for children with ASD, including natural products, mind and body practices, and other biomedical treatments. The article focuses on factors associated with use of CAM, the empirical evidence for the most frequently used treatments, and how clinicians work with families who choose CAM treatments. Some treatments have been ineffective, some have unacceptable potential side effects, and others require more study in depth.

Pyrosequencing study of fecal microflora of autistic and control children

There is evidence of genetic predisposition to autism, but the percent of autistic subjects with this background is unknown. It is clear that other factors, such as environmental influences, may play a role in this disease. In the present study, we have examined the fecal microbial flora of 33 subjects with various severities of autism with gastrointestinal symptoms, 7 siblings not showing autistic symptoms (sibling controls) and eight non-sibling control subjects, using the bacterial tag encoded FLX amplicon pyrosequencing (bTEFAP) procedure. The results provide us with information on the microflora of stools of young children and a compelling picture of unique fecal microflora of children with autism with gastrointestinal symptomatology. Differences based upon maximum observed and maximum predicted operational taxonomic units were statistically significant when comparing autistic and control subjects with p-values ranging from <0.001 to 0.009 using both parametric and non-parametric estimators. At the phylum level, Bacteroidetes and Firmicutes showed the most difference between groups of varying severities of autism. Bacteroidetes was found at high levels in the severely autistic group, while Firmicutes were more predominant in the control group. Smaller, but significant, differences also occurred in the Actinobacterium and Proteobacterium phyla. Desulfovibrio species and Bacteroides vulgatus are present in significantly higher numbers in stools of severely autistic children than in controls. If the unique microbial flora is found to be a causative or consequent factor in this type of autism, it may have implications with regard to a specific diagnostic test, its epidemiology, and for treatment and prevention.