ABSTRACT

Background: Recent studies have reveled the presence of a complex fungal community (mycobiome) in the oral cavity. However, the role of oral mycobiome in dental caries and its interaction with caries-associated bacteria is not yet clear.

Methods: Whole-mouth supragingival plaque samples from 30 children (6–10 years old) with no caries, early caries, or advanced caries were sequenced for internal transcribed spacer 2 (ITS-2). The mycobiome profiles were correlated with previously published bacteriome counterparts. Interaction among selected fungal and bacterial species was assessed by co-culture or spent media experiments.

Results: Fungal load was extremely low. Candida, Malassezia, Cryptococcus, and Trichoderma spp. were the most prevalent/abundant taxa. Advanced caries was associated with significantly higher fungal load and prevalence/abundance of Candida albicans. Cryptococcus neoformans and Candida sake were significantly over-abundant in early caries, while Malassezia globosa was significantly enriched in caries-free subjects. C. albicans correlated with Streptococcus mutans and Scardovia wiggsiae among other caries-associated bacteria, while M. globosa inversely correlated with caries-associated bacteria. In-vitro, M. globosa demonstrated inhibitory properties against S. mutans.

Conclusions: the results substantiate the potential role of the oral mycobiome, primarily Candida species, in dental caries. Inter-kingdom correlations and inhibition of S. mutans by M. globosa are worth further investigation.

摘要

背景：最近的研究揭示了口腔中存在复杂的真菌群落（菌群）。但是，口腔真菌基因组在龋齿中的作用及其与龋齿相关细菌的相互作用尚不清楚。

方法：对30例无龋齿，早期龋齿或晚期龋齿的儿童的全口龈上牙菌斑样本进行了内部转录间隔区2（ITS-2）测序。真菌基因组谱与先前发表的细菌组对应物相关。通过共培养或用过的培养基实验来评估所选真菌和细菌种类之间的相互作用。

结果：真菌负荷极低。念珠菌，马拉色菌，隐球菌和木霉属。是最普遍/最丰富的分类单元。晚期龋病与白色念珠菌的真菌载量和患病率/丰富度显着相关。在早期龋齿中，新隐球菌和假丝酵母明显过量，而在无龋齿的受试者中，球形马拉色菌明显丰富。白色念珠菌与变形链球菌和Scardovia wiggsiae与其他龋齿相关细菌有关，而球形念珠菌与龋齿相关细菌呈负相关。在体外，球形分支杆菌表现出对变形链球菌的抑制特性。

结论：结果证实了口腔真菌生物组（主要是念珠菌）在龋齿中的潜在作用。王国之间的关联和变形链球菌对球形链球菌的抑制值得进一步研究。