College of Stomatology, Chongqing Medical University, Chongqing, China.
Chongqing key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China.
Oral Dis. 2018 Sep;24(6):1115-1125. doi: 10.1111/odi.12871. Epub 2018 Jun 19.
The mixed dentition is an important transition period from primary teeth to permanent teeth. However, the caries prevalence of first permanent molar in mixed dentitions was about 30%, which almost represent the caries rate of permanent teeth in this period of time. Therefore, we assessed the oral bacterial profiles in young children (age 6-8) with mixed dentition with or without first molar caries for providing the research basis of caries etiology.
We collected samples of supragingival plaque and saliva from the children living in Guizhou, a rural isolated province in China. Then, we performed DNA extraction and purification followed by 454 pyrosequencing of the V1-V3 hypervariable regions of the 16S rRNA and compared our results with those of previous research.
(i) We analyzed 48,320 unique sequences that represented 18 phyla, 29 classes, 44 orders, 74 families, 129 genera, 15,003 species-level OUT in plaque and saliva samples; (ii) longitudinally, there was the "healthy core microbiome" between healthy deciduous dentition and early mixed dentition, for example, Neisseria, Porphyromonas, Selenomonas etc.; (iii) horizontally, there also existed the "healthy core microbiome" in early mixed dentition, for example, Neisseria, Streptococcus, Prevotella etc.; (iv) the dominant bacteria detected by Lefse in caries group including Actinomycetaceae, Streptobacillus (p < 0.05) and those in caries-free group including Gammaproteobacteria, Pasteurellaceae, Aggregatibacter, Chloroflexi, (p < 0.05).
The oral cavity is a highly heterogeneous ecosystem with the "healthy core microbiome" in children, although microbial composition shifts along with aging. In addition, the abundance and diversity of microbiota vary between caries and caries-free groups verify the ecological plaque hypothesis.
混合牙列是从乳牙到恒牙的重要过渡时期。然而，混合牙列中第一恒磨牙的龋齿患病率约为 30%，这几乎代表了这个时期恒牙的龋齿率。因此，我们评估了患有混合牙列且有或无第一恒磨牙龋齿的幼儿的口腔细菌谱，为龋齿病因学研究提供了依据。
我们收集了来自中国贵州省农村隔离地区的儿童的龈上菌斑和唾液样本。然后，我们进行 DNA 提取和纯化，随后对 16S rRNA 的 V1-V3 高变区进行 454 焦磷酸测序，并将结果与以前的研究进行比较。
（i）我们分析了菌斑和唾液样本中 48,320 个独特的序列，这些序列代表了 18 个门、29 个纲、44 个目、74 个科、129 个属、15,003 个种水平的 OUT；（ii）从纵向来看，在健康的乳牙和早期混合牙列之间存在“健康核心微生物组”，例如奈瑟菌属、卟啉单胞菌属、唾液单胞菌属等；（iii）从横向来看，在早期混合牙列中也存在“健康核心微生物组”，例如奈瑟菌属、链球菌属、普雷沃菌属等；（iv）Lefse 检测到龋齿组中优势菌包括放线菌科、链球菌属（p<0.05），无龋齿组中优势菌包括γ-变形菌纲、巴斯德氏菌科、Aggregatibacter、Chloroflexi（p<0.05）。
尽管微生物组成会随着年龄的增长而发生变化，但儿童的口腔是一个高度异质的生态系统，存在“健康核心微生物组”。此外，龋齿组和无龋齿组的微生物群落丰度和多样性的差异验证了生态菌斑假说。
