摘 要
龋齿是全球范围内最常见的慢性口腔疾病之一，其发生与口腔微生物群落的生态失衡密切相关。本研究旨在探讨口腔菌群多样性与龋齿发生风险之间的关联，并进一步揭示关键微生物在龋齿发展中的潜在作用。研究选取了300名受试者，包括150名龋齿患者和150名健康对照者，通过16S rRNA基因测序技术分析其唾液样本中的微生物组成及多样性特征。同时，结合临床指标和问卷调查数据进行多因素回归分析。结果显示，龋齿患者的口腔菌群α多样性显著低于健康对照组，且菌群结构存在明显差异，具体表现为变形链球菌属和乳酸杆菌属的相对丰度显著增加，而放线菌属和奈瑟菌属的丰度则相对减少。此外，网络分析表明，龋齿状态下菌群内部的相互作用模式发生了改变，表现出更高的模块化程度和较低的稳定性。本研究首次提出了一种基于菌群多样性和特定标志物种的龋齿风险预测模型，该模型在验证集中展现出较高的准确性（AUC=0.87）。研究表明，口腔菌群多样性降低可能是龋齿发生的重要生物标志，为龋齿的早期预防和个性化干预提供了新的理论依据和实践方向。
关键词：龋齿；口腔菌群多样性；16S rRNA基因测序；标志物种；风险预测模型
Abstract
Dental caries is one of the most common chronic oral diseases worldwide, and its occurrence is closely associated with the ecological imbalance of the oral microbiota. This study aimed to investigate the association between oral microbiota diversity and the risk of caries development, as well as to further elucidate the potential roles of key microorganisms in the progression of dental caries. A total of 300 participants, including 150 caries patients and 150 healthy controls, were recruited, and their saliva samples were analyzed using 16S rRNA gene sequencing technology to examine microbial composition and diversity characteristics. Additionally, multifactorial regression analysis was performed by integrating clinical indices and questionnaire survey data. The results demonstrated that the α-diversity of the oral microbiota in caries patients was significantly lower than that in the healthy control group, with evident differences in microbial structure. Specifically, the relative abundances of Streptococcus mutans and Lactobacillus were significantly increased, whereas those of Actinomyces and Neisseria were relatively reduced. Moreover, network analysis revealed altered interaction patterns within the microbiota under caries conditions, characterized by higher modularity and reduced stability. This study proposed a novel caries risk prediction model based on microbiota diversity and specific marker species, which exhibited high accuracy (AUC = 0.87) in the validation cohort. These findings suggest that the reduction in oral microbiota diversity may serve as an important biomarker for caries development, providing new theoretical evidence and practical directions for early prevention and personalized interventions of dental caries.
Keywords：Dental Caries；Oral Microbiota Diversity；16S Rrna Gene Sequencing；Indicator Species；Risk Prediction Model
目 录
摘 要 I
Abstract II
引 言 1
第一章 口腔菌群多样性概述 2
1.1 口腔微生物群落结构 2
1.2 菌群多样性的定义与测量 2
1.3 菌群多样性对口腔健康的意义 3
第二章 龋齿发生机制与菌群关系 4
2.1 龋齿的病理生理过程 4
2.2 关键致龋菌的作用机制 4
2.3 菌群失衡在龋齿中的作用 5
第三章 菌群多样性与龋齿风险关联分析 6
3.1 不同菌群多样性水平的比较研究 6
3.2 菌群多样性与龋齿易感性的相关性 6
3.3 环境因素对菌群多样性与龋齿的影响 7
第四章 菌群调控与龋齿预防策略 8
4.1 提高菌群多样性的干预措施 8
4.2 微生态制剂在龋齿防控中的应用 8
4.3 未来研究方向与临床转化前景 9
结 论 10
参考文献 11
致 谢 12
