Enzo Grossi, Vittorio Terruzzi MD
Human microbiota represents one of the most striking cultural revolution in medicine emerged in the last 20 years. Many studies have revealed how the complexity and dynamics of gut microbiota influences normal physiology and contribute to a variety of diseases ranging from obesity to atherosclerosis, allergy and severe neurological disorders. The latter topic is of particular relevance and really revolutionary and is specifically linked to the existence of so-called gut-brain axis: a physiological frame-work in which the gut microbiota communicates with the CNS and vice-versa through neural, endocrine and immune pathways. If this is true then is plausible to expect that the modulation gut microbiota may be a tractable strategy for developing novel therapeutics for complex CNS disorders. Autism is definitely one of these disorders.
Autism encompasses a broad spectrum of heterogeneous neurodevelopmental disorders with a prevalence rate of 1:150 and a 4:1 male: female ratio, characterized by qualitative impairment in social communication area and restricted repetitive and stereo-typed patterns of behavior interests and activities.
The possibility that autism is the consequence of an imperfect development of gut flora is supported by a number of observations like: the frequent coexistence of gastrointestinal symptoms in autistic children; the appearance of the disease after an incidental antimicrobic therapy and the increased levels of urinary biomarkers of specific pathogens of clostridium spp. in the urine of autistic children.
SCFAs represent a group of compounds derived from the host microbiome that can induce widespread effects on gut, brain, and behavior, contribute to various neurological processes and are plausibly linked to ASDs.
Since the literature about the role played by intestinal dysbiosis in autism is increasing, we felt interesting to summarize the present evidences in this mini review.