Characteristics and functions of the gut microbiome in monozygotic twins with autism spectrum disorders of varying severity

Despite similar overall diversity, children with severe ASD exhibited distinct gut microbiota structures and functional impairments. The enrichment of <i>Porphyromonas</i>, along with the reduced expression of genes involved in carbohydrate metabolism and stress responses in the high-severity group, suggests an association between gut microbial dysregulation and ASD severity. These findings provide new insights into microbiota-related mechanisms underlying ASD and highlight potential functional targets for intervention.