University of Valencia, Stomatology Department, Gascó Oliag 1, Valencia, Spain.
Department of Genomics and Health, Centre for Advanced Research in Public Health, CSISP-FISABIO, Valencia, Spain.
PLoS One. 2018 Jun 1;13(6):e0198021. doi: 10.1371/journal.pone.0198021. eCollection 2018.
Epidemiological studies use saliva on a regular basis as a non-invasive and easy-to-take sample, which is assumed to be a microbial representative of the oral cavity ecosystem. However, comparative studies between different kinds of saliva samples normally used in microbial studies are scarce. The aim of the current study was to compare oral microbiota composition between two different saliva samples collected simultaneously: non-stimulated saliva with paper points and stimulated saliva collected after chewing paraffin gum. DNA was extracted from saliva samples of ten individuals, then analyzed by 16S rRNA pyrosequencing to describe bacterial diversity. The results demonstrate significant differences between the microbiota of these two kinds of saliva. Stimulated saliva was found to contain an estimated number of species over three times higher than unstimulated saliva. In addition, bacterial composition at the class and genus level was radically different between both types of samples. When compared to other oral niches, both types of saliva showed some similarity to tongue and buccal mucosa, but they do not correlate at all with the bacterial composition described in supra- or sub-gingival dental plaque, questioning their use in etiological and epidemiological studies of oral diseases of microbial origin.
流行病学研究经常使用唾液作为非侵入性和易于采集的样本，认为其是口腔生态系统的微生物代表。然而，用于微生物研究的不同类型唾液样本之间的比较研究很少。本研究旨在比较两种同时采集的唾液样本（用滤纸拭子采集的非刺激唾液和咀嚼石蜡口香糖后采集的刺激唾液）之间的口腔微生物群落组成。从十个人的唾液样本中提取 DNA，然后通过 16S rRNA 焦磷酸测序进行分析以描述细菌多样性。结果表明，这两种唾液的微生物群落存在显著差异。刺激唾液中估计的物种数量是未刺激唾液的三倍以上。此外，两种类型的样本在类和属水平上的细菌组成也有很大差异。与其他口腔生态位相比，这两种唾液与舌和颊黏膜有一定的相似性，但与龈上或龈下牙菌斑中描述的细菌组成完全不相关，这对其在口腔疾病的病因学和流行病学研究中的应用提出了质疑。
