健康成人口腔微生物组成及功能的宏基因组学研究

Metagenomic study on the composition and function of oral microorganisms in healthy adults

目的基于宏基因组学测序探究健康成人唾液和龈上菌斑微生态的物种组成及功能基因代谢途径,为口腔疾病的生物学防治提供参考。方法采集健康成人唾液和龈上菌斑样本,分别提取样本总DNA,构建宏基因组文库,对合格的文库进行宏基因组学测序,并对测序数据进行生物信息学及统计学分析。结果健康口腔样本主要菌门为变形菌门(32.51%)、拟杆菌门(30.81%)、放线菌门(16.23%)等,主要菌种为马氏棒状杆菌(3.84%)、副流感嗜血菌(2.91%)、产黑色素普雷沃菌(2.76%)等;龈上菌斑组的Alpha多样性高于唾液组,且两组间微生物群落构成存在明显差异(P<0.05)。在种水平上,唾液样本中产黑色素普雷沃菌、牙周梭杆菌、中间普雷沃菌等较龈上菌斑样本丰富,而龈上菌斑样本中马氏棒状杆菌、产酸丙酸杆菌、龋齿罗氏菌等比唾液样本丰富(P<0.05)。基于宏基因组学测序构建了健康成人唾液及龈上菌斑的高质量基因集。KEGG通路功能代谢差异结果显示唾液微生物中淀粉与蔗糖代谢、亮氨酸和异亮氨酸降解、精氨酸生物合成等较龈上菌斑丰富,而龈上菌斑中糖酵解/糖合成、碳代谢等较唾液丰富。结论健康成人唾液和龈上菌斑微生态的物种组成及功能基因代谢途径存在明显差异,不同微生态区的优势物种对识别口腔疾病的敏感性可能不同,在口腔疾病微生物研究中,应根据研究疾病的不同选择合适的样本。

Objective Metagenomic sequencing was used to explore the species composition and internal functional metabolic pathway of saliva and supragingival plaque microbial communities in healthy adults to provide a theoretical reference for the biological prevention and treatment of oral diseases.Methods Saliva and supragingival plaque samples were collected from healthy adults,total DNA was extracted,and a metagenomic library was constructed.The qualified library was sequenced via metagenomics,and the sequencing data were analyzed using bioinformatics and statistics.Results The main bacterial phyla in healthy oral samples were Proteobacteria (32.51%),Bacteroidetes (30.81%),and Actinobacteria (16.23%),and the main bacterial species were Corynebacterium matruchotii (3.84%),Haemophilus parainfluenzae (2.91%),and Prevotella melaninogenica (2.76%).The alpha diversity of the supragingival plaque group was higher than that of the saliva group,and there was a significant difference in the composition of the microbial community between the two groups (P<0.05).At the species level,Prevotella melaninogenica,Fusobacterium periodonticum,and Prevotella intermedia were more abundant in saliva samples than in supragingival plaque samples,while Corynebacterium matruchotii,Propionibacterium acidifaciens,and Rothia dentocariosa were more abundant in supragingival plaque samples than in saliva samples (P<0.05).High-quality gene sets of saliva and supragingival plaque in healthy adults were constructed based on metagenomic sequencing.The results of KEGG pathway functional metabolic differences showed that starch and sucrose metabolism,leucine and isoleucine degradation,and arginine biosynthesis in salivary microorganisms were more abundant than in supragingival plaque,while glycolysis/gluconeogenesis and carbon metabolism in supragingival plaque were more abundant than in saliva.Conclusion There are significant differences in the species composition and functional gene metabolic pathways of saliva and supragingival plaque microecology in healthy adults.The sensitivity of dominant species in different microecological regions to the identification of oral diseases may be different.In the microbiological study of oral diseases,appropriate samples should be selected according to different diseases.