Oral Microecology in Children With Autism

1. Research Background Autism spectrum disorder (ASD) is a pervasive developmental disorder that has become the leading cause of mental disability in children in China. The onset of autism is closely related to genetic factors and environmental factors in early development. In recent years, studies have found that changes in gut microbiota are related to the pathogenesis of ASD.

Salivary immunoglobulin A (IgA) is the main protective antibody in oral mucosal immunity, which, together with the innate immune system, inhibits the adhesion of microorganisms to the mucosa and tooth surface, promotes the elimination of cariogenic microorganisms such as Streptococcus mutans. Given the changes in oral health status in ASD patients and the correlation between oral microbiota dysbiosis and mucosal immunity, the level of salivary IgA affected by oral bacteria may vary in ASD subjects.

Oral microbiota may have direct or indirect effects on the brain. Bacteria can enter the bloodstream through mucous membranes and tooth roots, break through the blood-brain barrier, and enter the brain; Oral associated bacteria can also promote the elevation of inflammatory factors in cerebrospinal fluid and affect the levels of neurotransmitters involved in learning and memory. There may be a certain connection between oral microbiota and the brain in children with ASD, with a "microbiota mouth brain axis". 2. Research objective

• Clarify the changes in IgA content and oral microbiota abundance in children with varying degrees of ASD; ② Clarify the changes in IgA content and oral microbiota abundance between ASD children and normal children groups; ③ Clarify the host's immune response under changes in oral microbiota.