DataSheet_1_Characteristics of oral microbiota in plateau and plain youth‐positive correlations between blood lipid level, metabolism and specific microflora in the plateau group.docx

ObjectivesTo analyze the characteristics of oral microbiota in plateau and plain youth and the possible function of the microbiome.
Materials and methodsA total of 120 healthy young males (80 on the plateau, 40 on the plain) completed this cross-sectional study. Oral microflora samples were collected from all participants. The bacterial 16S rDNA was amplified using PCR and sequenced using Illumina MiSeq high-throughput sequencing. The data were analyzed to determine the microbial distribution and community structure of the oral microflora from the two groups. Metastats was used to test differences in relative species abundance between the groups. The correlation between the abundance of specific bacteria and blood indicators was also analyzed.
ResultsAs demonstrated by alpha and beta diversity, the plateau group had lower microbial richness and a less even distribution of oral microbiota than the plain group. All predominant phyla and genera were qualitatively similar between the two groups, but their relative abundances differed. The relative abundance of bacteria in the phylum Firmicutes was significantly higher in the plateau group than in the plain group. At the genus level, Streptococcus spp. and Gemella spp. were also more abundant in the plateau group. The functional prediction indicated vigorous microbial metabolism in the oral bacterial community. We also found that the relative abundance of Streptococcus spp., the dominant genus, was positively correlated with triglyceride levels in the plateau group.
ConclusionsWith increasing altitude, the diversity of oral microbiota and the relative proportion of predominant bacteria were altered. The distribution and related function of Streptococcus spp. were prominent in plateau samples. This comprehensive study of the relationship between oral microecology and elevation provides a point of reference for studying the human body’s adaptability or inadaptability to high altitude.

研究目的：分析高原与平原青年口腔微生物群（oral microbiota）的特征及其微生物组（microbiome）的潜在功能。
材料与方法：本项横断面研究共纳入120名健康青年男性，其中高原组80名，平原组40名。所有受试者均采集口腔微生物群样本。采用聚合酶链式反应（PCR）扩增细菌16S核糖体DNA（16S rDNA），并通过Illumina MiSeq高通量测序平台完成测序。对测序数据进行分析，以明确两组口腔微生物群的微生物分布特征与群落结构；采用Metastats检验两组间物种相对丰度的组间差异；同时分析特定细菌丰度与血液指标的相关性。
研究结果：α多样性（alpha diversity）与β多样性（beta diversity）分析结果显示，相较于平原组，高原组口腔微生物群的丰富度更低，群落分布均匀性更差。两组间优势菌门与优势菌属的种类无定性差异，但相对丰度存在显著不同。厚壁菌门（Firmicutes）细菌的相对丰度在高原组中显著高于平原组；在属水平上，链球菌属（Streptococcus）与孪生球菌属（Gemella）的相对丰度在高原组中同样更高。功能预测结果表明，口腔细菌群落的代谢活动较为旺盛。此外，在高原组中，作为优势菌属的链球菌属的相对丰度与甘油三酯水平呈正相关。
研究结论：随着海拔升高，口腔微生物群的多样性以及优势菌的相对占比均发生改变；链球菌属的分布与相关功能在高原样本中表现突出。本项针对口腔微生态与海拔梯度关系的综合性研究，可为探讨人体对高海拔环境的适应性或不适应性机制提供参考依据。