Metataxonomic and immunological analysis of feces from chil-dren with or without Phelan-McDermid syndrome

Phelan-McDermid syndrome (PMS) is a neurodevelopmental disorder characterized by global developmental delay and autistic behaviors. Emerging research suggests a link between gut mi-crobiota and neuropsychiatric conditions, including PMS, given its high prevalence of autism spectrum disorder (ASD)-like behaviors. This study aimed to investigate the fecal microbiota and immune profiles of children with PMS compared to healthy controls. Fecal samples were collected from children diagnosed with PMS and age-matched healthy controls. The bacterial composition was analyzed using 16S rRNA gene sequencing, while short-chain fatty acids (SCFAs) were quantified through gas chromatography. Immunological profiling was conducted using a mul-tiplex cytokine assay. Significant differences were observed in the gut microbiota composition between PMS patients and controls, including a lower abundance of key bacterial genera such as Faecalibacterium and Agathobacter in PMS patients. SCFA levels were also reduced in PMS patients. Immunological analysis revealed higher levels of several pro-inflammatory cytokines in the PMS group, although these differences were not statistically significant. The findings indicate that children with PMS have distinct gut microbiota and immune profiles, which may contribute to the gastrointestinal and neurodevelopmental symptoms observed in this syndrome. These results suggest potential avenues for microbiota-targeted therapies in PMS.