A Novel Multi-dimensional Prospective Study of the Gut-brain Axis Through Metabolic MRI, Metabolomics and Gut Microbiome to Discover Gene-microenvironment Interactions in Neurodevelopmental Disorders

Autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD) are common neurodevelopmental disorders in Taiwan and worldwide (prevalence rate, ASD, 1%; ADHD, 3-10%), presenting as clinically and genetically heterogeneous disorders with early onset at childhood lasting to adulthood. Both disorders bring a tremendous impact on individuals, families, and society. Despite extensive studies on these two disorders, our knowledge about their pathogenetic mechanism is still minimal, and there are no biomarkers for effective prevention, early detection, diagnosis and biological treatment (ineffective in 30% ADHD patients, none for ASD). Although they have distinct symptom inclusion criteria and intervention, emerging evidence suggests that ASD and ADHD may share some genetic influences and susceptibility involving neuroanatomical phenotypes, cognitive deficits, and behavioral phenotypes. However, few studies have investigated these two disorders simultaneously. Moreover, the role of metabolomics and microbiome in neuropsychiatric disorders has drawn much attention recently. With the PI's long-term commitment to the neurocognitive/imaging/gene research ADHD and ASD in separate projects, our knowledge about these two disorders improved, but their underlying pathogenesis remains unclear. Hence, a multi-dimensional prospective gut-brain axis integration study highlighting the metabolism in the whole body to identify the common and unique factors of these two disorders and discover their gene-microenvironment interaction mechanism is extremely urgent and warranted.

Specific Aims:

1. To identify and compare the early environmental factors (e.g., maternal, and pre-, peri-, and post-natal factors) affecting the gut- microbiome, cognition, and brain structures and functions among the ASD, ADHD and TDC groups at ages of 4-12 years old;
2. To investigate the symptomatology, neuropsychology, neuroimaging, gut microbiome and metabolic biomarker signatures at Time 1 and Time 2 among the three groups while considering food, GI symptoms, and life style;
3. To investigate the changes (Time2-Time1), stability, and interactions of the symptomatology, neuropsychology, neuroimaging (MRI+MRS), gut microbiome and metabolic biomarker signatures in youths with ASD and ADHD as compared to TDC over a 2-4-year follow-up period.
4. To identify the predictors from the environmental (perinatal, food, lifestyle, family, school, neighborhood) and individual (behavior, gut microbiota, metabolomics, brain structure) factors for the neurocognitive/brain function and psychosocial outcomes in the follow-up.