Department of Oral Biology, School of Dental Medicine, University at Buffalo, State University of New York, Buffalo, NY, USA.
UB Microbiome Center, University at Buffalo, State University of New York, Buffalo, NY, USA.
J Dent Res. 2021 Feb;100(2):133-140. doi: 10.1177/0022034520956975. Epub 2020 Sep 13.
Recent efforts to understand the oral microbiome have focused on its fungal component. Since fungi occupy a low proportion of the oral microbiome biomass, mycobiome studies rely on sequencing of internal transcribed spacer (ITS) amplicons. ITS-based studies usually detect hundreds of fungi in oral samples. Here, we review the oral mycobiome, critically appraising the significance of such large fungal diversity. When harsh lysis methods are used to extract DNA, 2 oral mycobiome community types (mycotypes) are evident, each dominated by only 1 genus, either or . The rest of the diversity in ITS surveys represents low-abundance fungi possibly acquired from the environment and ingested food. So far, is the only genus demonstrated to reach a significant biomass in the oral cavity and clearly shown to be associated with a distinct oral ecology. thrives in the presence of lower oral pH and is enriched in caries, with mechanistic studies in animal models suggesting it participates in the disease process by synergistically interacting with acidogenic bacteria. serves as the main etiological agent of oral mucosal candidiasis, in which a -bacteriome partnership plays a key role. The function of other potential oral colonizers, such as lipid-dependent , is still unclear, with further studies needed to establish whether are metabolically active oral commensals. Low-abundance oral mycobiome members acquired from the environment may be viable in the oral cavity, and although they may not play a significant role in microbiome communities, they could serve as opportunistic pathogens in immunocompromised hosts. We suggest that further work is needed to ascertain the significance of oral mycobiome members beyond . ITS-based surveys should be complemented with other methods to determine the in situ biomass and metabolic state of fungi thought to play a role in the oral environment.
最近，人们致力于研究口腔微生物组的真菌组成部分。由于真菌在口腔微生物组生物量中所占比例较低，因此真菌组研究依赖于内部转录间隔区（ITS）扩增子的测序。基于 ITS 的研究通常在口腔样本中检测到数百种真菌。在这里，我们综述了口腔真菌组，并批判性地评价了这种大型真菌多样性的意义。当使用苛刻的裂解方法提取 DNA 时，有 2 种口腔真菌组群落类型（真菌型）显而易见，每种类型仅由 1 个属主导，要么是 ，要么是 。ITS 调查中其余的多样性代表了可能从环境和摄入的食物中获得的低丰度真菌。到目前为止，只有 被证明在口腔中有显著的生物量，并且清楚地表明与独特的口腔生态环境有关。 在较低的口腔 pH 值存在下茁壮成长，在龋齿中富集，动物模型的机制研究表明，它通过与产酸菌协同作用参与疾病过程。 是口腔黏膜念珠菌病的主要病因，其中 - 细菌组伙伴关系发挥着关键作用。其他潜在的口腔定植菌，如依赖脂质的 ，的功能仍然不清楚，需要进一步研究来确定 是否是具有代谢活性的口腔共生菌。从环境中获得的低丰度口腔真菌组成员可能在口腔中具有活力，尽管它们在微生物组群落中可能没有发挥重要作用，但它们可能成为免疫功能低下宿主中的机会性病原体。我们建议，需要进一步的研究来确定 以外的口腔真菌组成员的意义。基于 ITS 的调查应辅以其他方法，以确定被认为在口腔环境中发挥作用的真菌的原位生物量和代谢状态。
