Table 8.

Summary of studies on oral microbiota in children with autism

Ref.	Population	Intervention	Comparison	Outcome	Study design	Key findings	Study quality rating
Kong et al[70], 2019	Children with ASD and neurotypical controls	Analysis of oral and gut microbiota using 16S rRNA sequencing	Neurotypical children	Identified distinct oral and gut microbiota signatures; explored microbial biomarkers for ASD diagnosis	Pilot study	ASD children had unique oral microbiota profiles with potential diagnostic biomarkers; suggested probiotics could alter microbiome and improve comorbid conditions	Moderate quality
Evenepoel et al[71], 2024	80 autistic children (8-12 years) and 40 neurotypical peers	Examination of oral microbiota differences using high-throughput sequencing	Typically developing children	ASD children had higher abundances of Solobacterium, Stomatobaculum, Ruminococcaceae UCG.014, Tannerella, and Campylobacter; associations found with social difficulties and anxiety	Cross-sectional study	Oral microbiome variations correlated with ASD symptom severity and were not significantly driven by lifestyle factors	High quality
Qiao et al[72], 2018	32 ASD children and 27 healthy controls	High-throughput sequencing of salivary and dental microbiota	Neurotypical children	ASD children had lower bacterial diversity, higher pathogenic bacteria (Haemophilus, Streptococcus), and reduced commensals (Prevotella, Fusobacterium, Actinomyces)	Case-control study	Significant microbiota differences in ASD children; proposed microbial markers for ASD diagnosis	Moderate

ASD: Autism spectrum disorder; rRNA: Ribosomal ribonucleic acid.