Many studies have reported abnormal gut microbiota in individuals with Autism Spectrum Disorders (ASD), suggesting a link between gut microbiome and autism-like behaviors.
The human gut and brain interact in complex ways, and abnormal conditions in the gut may predispose individuals to neurodevelopmental disorders. Individuals with Autism Spectrum Disorders (ASD), Parkinson’s disease, and Alzheimer’s disease, have been known to experience chronic gastrointestinal (GI) symptoms as a common co-occurring medical condition, suggesting the presence of a gut-brain axis. In a study of 192 twin pairs they found that both genetic and environmental factors contribute to the etiology of ASD.
The gut microbiome represents an important environmental factor that may exert an influence on symptoms, and a growing number of research groups have observed that children with ASD have distinctive gut microbiomes compared to children without ASD symptoms. More importantly, multiple mouse studies have reported that gut microbes and their metabolites can impact behavior through the gut-brain axis, including for ASD.
Considering the link between the gut and brain, modulating the gut microbiome by probiotics, prebiotics, and/or fecal microbiota transplant (FMT) could be a viable therapeutic option. In FMT, a large diversity and number of commensal microbes from a healthy donor are used to transform a dysbiotic gut microbiome into a healthy microbiome.
Modifying the gut microbiome is a potential route to improve gastrointestinal (GI) and behavioral symptoms in children with ASD, and fecal microbiota transplant could transform the dysbiotic gut microbiome toward a healthy one by delivering a large number of commensal microbes from a healthy donor.
In this study they report a follow-up with 18 participants two years after FMT treatment was completed. Notably, most improvements in GI symptoms were maintained, and autism-related symptoms improved even more after the end of treatment around 50% improvement. Also important changes in gut microbiota at the end of treatment remained at follow-up, including significant increases in bacterial diversity and relative abundances of Bifidobacteria and Prevotella. These observations demonstrate the long-term safety and efficacy of MTT as a potential therapy to treat children with ASD who have GI problems, and warrant a double-blind, placebo-controlled trial in the future.