Abstract：
OBJECTIVE: To examine association between subgingival microbial signatures and levels of cognitive impairment in older adults.
METHODS: We analysed subgingival plaque samples and 16S ribosomal RNA sequences for microbiota among 165 participants (normal controls [NCs]: 40, subjective cognitive decline [SCD]: 40, mild cognitive impairment [MCI]: 49 and dementia: 36).
RESULTS: The bacterial richness was lower among individuals with worse cognitive function, and subgingival microbial communities differed significantly among the four groups. Declining cognitive function was associated with decreasing relative abundance of genera Capnocytophaga, Saccharibacteria_genera_incertae_sedis, Lautropia and Granulicatella, and increasing abundance of genus Porphyromonas. Moreover, there were differentially abundant genera among the groups. Random forest model based on subgingival microbiota could distinguish between cognitive impairment and NC (AUC = 0.933, 95% confidence interval 0.873-0.992). Significant correlations were observed between oral microbiota and sex, Montreal Cognitive Assessment (MoCA) score and Mini-Mental State Examination score. Partial correlation analysis showed that Leptotrichia and Burkholderia were closely negatively associated with the MoCA score after adjusting for multiple covariates. Gene function was not significantly different between SCD and NC groups, whereas three homozygous genes were altered in MCI patients and two in dementia patients.
CONCLUSIONS: This is the first study to demonstrate an association between the composition, function and metabolic pathways of subgingival microbiota and different levels of cognitive function among older individuals. Future cohort studies should assess its diagnostic usefulness for cognitive impairment.
METHODS: We analysed subgingival plaque samples and 16S ribosomal RNA sequences for microbiota among 165 participants (normal controls [NCs]: 40, subjective cognitive decline [SCD]: 40, mild cognitive impairment [MCI]: 49 and dementia: 36).
RESULTS: The bacterial richness was lower among individuals with worse cognitive function, and subgingival microbial communities differed significantly among the four groups. Declining cognitive function was associated with decreasing relative abundance of genera Capnocytophaga, Saccharibacteria_genera_incertae_sedis, Lautropia and Granulicatella, and increasing abundance of genus Porphyromonas. Moreover, there were differentially abundant genera among the groups. Random forest model based on subgingival microbiota could distinguish between cognitive impairment and NC (AUC = 0.933, 95% confidence interval 0.873-0.992). Significant correlations were observed between oral microbiota and sex, Montreal Cognitive Assessment (MoCA) score and Mini-Mental State Examination score. Partial correlation analysis showed that Leptotrichia and Burkholderia were closely negatively associated with the MoCA score after adjusting for multiple covariates. Gene function was not significantly different between SCD and NC groups, whereas three homozygous genes were altered in MCI patients and two in dementia patients.
CONCLUSIONS: This is the first study to demonstrate an association between the composition, function and metabolic pathways of subgingival microbiota and different levels of cognitive function among older individuals. Future cohort studies should assess its diagnostic usefulness for cognitive impairment.
摘要：
目的：研究老年人牙龈下微生物特征与认知障碍水平之间的关系。
方法：我们分析了165名参与者（正常对照[NC]：40，主观认知下降[SCD]：40，轻度认知障碍[MCI]：49和痴呆：36）的龈下菌斑样本和16S核糖体RNA序列。
结果：认知功能较差的个体的细菌丰富度较低，牙龈下微生物群落在四组之间存在显着差异。认知功能下降与Capnocytophaga属的相对丰度降低有关，杆菌属，Lautropia和Granulicatella,和越来越丰富的卟啉菌属。此外，群体之间存在差异丰富的属。基于牙龈下微生物群的随机森林模型可以区分认知障碍和NC（AUC=0.933，95％置信区间0.873-0.992）。口腔微生物群与性别之间存在显著相关性，蒙特利尔认知评估（MoCA）得分和简易精神状态检查得分。偏相关分析表明，在调整多个协变量后，Leptotrichia和Burkholderia与MoCA评分呈负相关。SCD组和NC组的基因功能无显著差异,而MCI患者有3个纯合基因改变，痴呆患者有2个。
结论：这是第一项证明组合物之间存在关联的研究，牙龈下微生物群的功能和代谢途径以及老年个体不同程度的认知功能。未来的队列研究应评估其对认知障碍的诊断价值。
方法：我们分析了165名参与者（正常对照[NC]：40，主观认知下降[SCD]：40，轻度认知障碍[MCI]：49和痴呆：36）的龈下菌斑样本和16S核糖体RNA序列。
结果：认知功能较差的个体的细菌丰富度较低，牙龈下微生物群落在四组之间存在显着差异。认知功能下降与Capnocytophaga属的相对丰度降低有关，杆菌属，Lautropia和Granulicatella,和越来越丰富的卟啉菌属。此外，群体之间存在差异丰富的属。基于牙龈下微生物群的随机森林模型可以区分认知障碍和NC（AUC=0.933，95％置信区间0.873-0.992）。口腔微生物群与性别之间存在显著相关性，蒙特利尔认知评估（MoCA）得分和简易精神状态检查得分。偏相关分析表明，在调整多个协变量后，Leptotrichia和Burkholderia与MoCA评分呈负相关。SCD组和NC组的基因功能无显著差异,而MCI患者有3个纯合基因改变，痴呆患者有2个。
结论：这是第一项证明组合物之间存在关联的研究，牙龈下微生物群的功能和代谢途径以及老年个体不同程度的认知功能。未来的队列研究应评估其对认知障碍的诊断价值。
