[Salivary microbial communities associated with severe early childhood caries].

To compare the salivary microbial profiles of healthy subjects and those with severe early childhood caries (S-ECC) by using high-throughput sequencing.Salivary samples were obtained from children with S-ECC (group C, n=24) and healthy children (group H, n=24). Total metagenomic DNA was extracted, and DNA amplicons of the V1-V3 hypervariable region of the 16S rRNA gene were generated and subjected to 454 sequencing. The characteristics of oral microbial communities from the two groups were compared based on microbial diversity and taxonomy assignment.First, the microbial richness was significantly higher in group C than group H (P<0.05). Second, the microbial community structure was significantly different for the groups H and C (P<0.01). In addition, caries microbiota was significantly conserved in group C (P<0.001). High expression of suspected cariogenic microorganisms in group C (P<0.1) and health related microorganisms in group H (P<0.1) were identified. Finally, models of caries risk assessment were proposed to distinguish caries from healthy subjects with over 70% accuracy.Salivary microbiota and certain taxa, such as caries-associated taxa (Prevotella), may be useful to screen/assess the children's risk of developing caries.目的 通过高通量测序技术研究重症低龄儿童龋病和健康者唾液的菌群结构及其差异。方法 在青岛市崂山区儿童中，经口腔检查选取健康（H组）和重症低龄龋病（C组）儿童各24名，采取唾液样本，提取其DNA进行聚合酶链式反应扩增，利用454测序平台对16S rRNA V1—V3区进行双端测序，对细菌群落结构及多样性进行差异分析。结果 C组唾液菌群物种丰度高于H组（P<0.05），两组唾液菌群结构的差异有统计学意义（P<0.01），且C组的群落结构更为相似和保守（P<0.001）；鉴别出C组高表达的可疑致龋微生物（P<0.1）及H组高表达的健康相关微生物（P<0.1）；基于唾液菌属图谱建立的龋病风险评估模型区分健康和龋病者的准确率可高达70%以上。结论 唾液菌群和特定细菌种类，如比例升高的Prevotella菌属有助于评估和筛选低龄儿童龋病风险。.