Welcome to Episode 6 in the CosmosID Microbiome Webinar Series where we’ll be exploring host-microbe symbiosis in autism spectrum disorders.
The onset of Autistic Spectrum Disorders is not yet clearly understood. With genetic predisposition playing only a minor role, the uncontrolled increase in the incidence of autism over the past few decades strongly supports the impact of environmental factors. Sometimes considered as such, the intestinal microbiota has been suggested as a key player in the etiology of autism. Variations in the composition of the intestinal microbiota reported in subjects with ASD have however been inconsistent. Many factors may explain this, such as the heterogeneity of analytical methods.
Conversely, more than the microbiota alone, alterations in host-microbes symbiosis could act as a key determinant, as is apparently the case for many immune-mediated chronic diseases. We will examine the potential association of an altered microbiota with intestinal permeability, inflammation and oxidative stress that could link intestinal disorders to brain-centered disorders and thus modify neuronal function and development.
The association between host-microbes symbiosis and autism could reconcile a rather large set of observations among which :
the much higher prevalence of gastrointestinal symptoms in autism compared to the general population (more than 50% versus 10-15%)
the ability to induce behavioural changes by transferring of the intestinal microbiota to germ-free animals
the occasional impact of antibiotics or probiotics on the symptoms of autism, their progression, or their ability to alleviate behavioural or cognitive specificities.
Clearly, from nutrition to dietary supplements to more radical interventions aimed at restoring host-microbes symbiosis through microbiota transfer, biologically targeted approaches should be evaluated in terms of their potential for improvement associated with the effectiveness of behavioral approaches. This would provide unique insights, as modulation of host-microbes symbiosis could affect gut health and, in turn, facilitate the alleviation of disorders.