The Role of the Microbiome in Autism: All That We Know about All That We Don't Know

Autism spectrum disorder (ASD) is a remarkably complex disorder influ-enced by both genetic and environmental factors. Numerous microbial diversity sur-veys conducted over the past decade have attempted to link specific ASD bio-markers to gastrointestinal tract disturbances, but results generated across cohorts and studies remain inconsistent. This commentary discusses multidirectional interac-tions between the host, the microbiome, and external factors germane to autism. Recent studies posit the heritability of the gut microbiome itself, confounding attempts to discern heritable from nonheritable effectors in neurodevelopmental dis-orders. Elucidating the ever-evolving gut microbiome's role in modulating the ASD phenotype will most certainly require new experimental methodologies and designs. In a recent paper published in mSystems (J. Fouquier, N. Moreno Huizar, J. Donnelly, C. Glickman, et al., mSystems e00848-20, 2021, https://doi.org/10.1128/mSystems .00848-20), the authors describe a web of interactions by collecting samples longi-tudinally, analyzing cross-sectional cohorts, and recording nonbinary phenotypic measurements.

Automated summary

Autism spectrum disorder (ASD) is a complex disorder influenced by genetic and environmental factors. Studies have suggested a role of the gut microbiome in modulating ASD phenotype, but results remain inconsistent. Future research will require new experimental methodologies to better understand this relationship.