学龄前儿童口腔不同生态位菌群特征的比较研究OA

Objective This study aims to investigate the structural differences,dominant bacterial genera,and po-tential functions of microbial communities in different oral ecological niches(dorsal tongue,tooth surface,and buccal mucosa)of preschool children to clarify the influence of local microenvironments on microbial colonization and pro-vide a theoretical basis for the microbiota-targeted regulation of pediatric oral diseases.Methods A total of 105 plaque samples were collected from the dorsal tongue,tooth surface,and buccal mucosa of 35 healthy preschool chil-dren(aged 4-6 years).High-throughput sequencing of the 16S rRNA gene was performed to analyze the microbial com-munity structure and alpha/beta diversity.Principal coordinate analysis,UPGMA clustering,and LEfSe analysis were used to identify niche-specific dominant genera.PIC-RUSt2 was applied to predict the potential metabolic functional profiles across niches.Results Spatial hete-rogeneity in microbial composition and structure was ob-served across the three oral niches.Species richness was significantly higher on the tooth surface and buccal mu-cosa than on the dorsal tongue.The dominant phyla included Firmicutes,Actinobacteria,Proteobacteria,Bacteroidetes,Fusobacteria,and Patescibacteria.At the genus level,Actinomyces and Corynebacterium were enriched on the tooth sur-face,Veillonella was enriched on the dorsal tongue,and Streptococcus was predominant on the buccal mucosa.Beta di-versity and clustering analyses confirmed distinct microbial community structures among the niches.LEfSe analysis identified several niche-specific genera.PICRUSt2 functional prediction revealed significant differences in amino acid metabolism,carbohydrate metabolism,cell motility,translation,signal transduction,immune system,infectious disea-ses,and membrane transport(P<0.05).Conclusion The dorsal tongue,tooth surface,and buccal mucosa in preschool children harbor distinct microbial communities with different taxonomic composition,diversity,and functional poten-tial.The findings suggest that local microenvironmental factors shape oral microbiota and may contribute to the early onset of oral diseases.This study provides foundational data and theoretical insights for early microbiome-based risk as-sessment and personalized oral health interventions in children.