Introduction: Nutrition and gut microbiota play a fundamental role in human health and various conditions such as Autism Spectrum Disorder (ASD). Children with ASD may have a restrictive diet due to increased sensory sensitivity or adherence to a glu

Introduction: Nutrition and gut microbiota play a fundamental role in human health and various conditions such as Autism Spectrum Disorder (ASD). Children with ASD may have a restrictive diet due to increased sensory sensitivity or adherence to a gluten-free and casein-free diet (GFCF). Therefore, the aim of this study was to analyze dietary intake, nutritional status, sensory profile, and gut microbiota in children with and without ASD.Methodology: A descriptive cross-sectional study was conducted with children aged 3 to 12 years (ASD = 35, typically developing (TD) = 30). Sensory profile and food frequency questionnaires were administered. Participants were categorized into normal weight and overweight, ASD-diet and ASD-no diet based on their adherence to GFCF diet. Intestinal bacteria were studied in fecal samples using 16S rRNA gene sequencing.Results: Children with ASD had higher intake of plant-based beverages (p=0.001) and gluten-free cereals (p=0.003), and lower consumption of fish (p<0.001) compared to those with TD. The ASD group showed increased sensory sensitivity based on the scores obtained in the sensory profile questionnaire (p<0.001) compared to TD children. Children with ASD had lower levels of Bifidobacterium longum and higher levels of Clostridium glycolicum compared to TD children. Participants with both ASD and overweight had lower levels of Roseburia, Faecalibacterium prausnitzii, and higher levels of Eubacterium ventriosum and Flavonifactor plautii compared to the TD group with the same nutritional status. Food intake (dairy products, plant-based beverages, gluten-containing and gluten-free cereals, protein-rich foods, fish, fat-rich foods, and coconut oil) was associated with gut microbiota, regardless of age, neurodevelopment (ASD/TD), and adherence to GFCF.Conclusions: These findings confirm the need to consider food intake, nutritional status, gut microbiota, neurodevelopment, and sensory profile, along with their associations, in the nutritional management of children with and without ASD. Further long-term research is needed to explore their impact on health.