Modulation of gut microbiota in autism spectrum disorders: a systematic review

Abstract

Abstract Background and objectives The identification of findings that suggest a unique dysbiotic microbial signature in Autism Spectrum Disorders (ASD), has drawn the attention towards promising therapies for ASD targeting gut-microbiota. In order to help physicians to make clinical decisions based on significant evidence, this work offers a systematic review of original peer-reviewed studies focused on microbiota-targeted treatments in ASD children. Methods The systematic review was conducted following the PRISMA guidelines. Quality of research was assessed using the National Health and Medical Research Council (NHMRC). Of 110 potential records initially identified, only 9 articles accomplished our inclusion criteria. Results A decrease in specific Clostridiales species and/or an increase in Bacillales was consistent in several studies after the microbiota-targeted interventions, whereas mixed results were seen in other phyla, congruent with different baseline trends in their ASD samples. Behavioral and GI function responses varied across interventions. Conclusion Preliminary data show microbiota-based therapies to have a positive effect on ASD patients. However, further well-designed, large-scale randomized controlled trials with standardized protocols are needed to support the effectiveness and safety of these treatments.