高真菌负荷老年人舌苔状态相关的舌部微生物群差异

文献信息

中文摘要

背景： 老年人的舌部微生物群需要特别关注，因为吞咽功能受损时它可能被吸入下呼吸道。本研究聚焦于高真菌负荷老年人中，有舌苔与无舌苔者舌部微生物群的差异。方法：我们首先使用针对真菌核糖体内部转录间隔区（ITS）的定量聚合酶链反应，对145名接受通勤康复服务的个体（平均年龄87.6 ± 6.5岁）舌部微生物群的总真菌负荷进行了定量。随后，基于真菌ITS区域和细菌16S rRNA基因扩增子测序，分别确定了58名高真菌负荷个体的真菌和细菌组成。结果：在无/轻度舌苔与明显舌苔个体之间（Winkel舌苔指数分别≤3和>3），舌部微生物群的真菌负荷和组成未观察到显著差异，且无论舌苔状态如何，白色念珠菌均为舌部微生物群的优势真菌物种。相比之下，与明显舌苔者相比，无/轻度舌苔个体的细菌负荷显著较低，且产酸类群（包括变形链球菌和加氏乳杆菌）的相对丰度较高。这些细菌群落也与无/轻度舌苔且低真菌负荷个体的细菌群落不同。结论：这些发现表明，老年人中伴随真菌过度生长的舌苔减少反映的是细菌群落的改变，而非真菌组成的差异。重要性：舌部微生物群状态需要特别关注，尤其是在老年人中，因为吞咽功能受损时微生物群可能被吸入下呼吸道，导致肺部感染。舌背上的细菌过度生长表现为舌苔积聚，可作为舌部卫生的指标。然而，老年人中真菌成分的增加有时伴随与良好舌部卫生无关的舌苔丧失，从而使视觉评估复杂化。本研究表明，伴随真菌过度生长的舌苔丧失反映了细菌群落改变与龋齿患病率增加的共同出现，提示龋齿风险更高。研究结果强调了在舌苔轻微的老年人中评估牙齿健康状况和舌部微生物群的重要性。

英文摘要

The tongue microbiota of older adults requires careful attention because it can be aspirated into the lower respiratory tract due to impaired swallowing function. This study focused on differences in the tongue microbiota of older adults with a high fungal load, with and without tongue coating. We initially quantified the total fungal load of tongue microbiota in 145 individuals receiving commuting rehabilitation services (mean age, 87.6 ± 6.5 years) using quantitative polymerase chain reaction targeting the fungal ribosomal internal transcribed spacer (ITS) region. The fungal and bacterial compositions of 58 individuals with high fungal loads were determined based on the fungal ITS region and bacterial 16S rRNA gene amplicon sequencing, respectively. No significant differences were observed in the fungal load and composition of the tongue microbiota between individuals with no/slight and substantial tongue coating (Winkel Tongue Coating Index ≤3 and >3, respectively), and Candida albicans was the predominant fungal species of the tongue microbiota regardless of the tongue coating status. In contrast, individuals with no/slight tongue coating exhibited significantly lower bacterial loads and higher relative abundances of acidogenic taxa, including Streptococcus mutans and Lactobacillus gasseri, compared with those with substantial tongue coating. These bacterial communities were also distinct from those of individuals with no/slight tongue coating and a low fungal load. These findings indicate that the reduction in tongue coating accompanied by fungal overgrowth in older adults reflects alterations in the bacterial community, rather than differences in fungal composition.IMPORTANCETongue microbiota status requires particular attention, especially among older adults, as microbiota can be aspirated into the lower respiratory tract due to impaired swallowing function, leading to pulmonary infections. Bacterial overgrowth on the tongue dorsum manifests as an accumulation of tongue coating, which serves as an indicator of tongue hygiene. However, an increase in fungal components in older adults is occasionally accompanied by a loss of tongue coating unrelated to good tongue hygiene, thereby complicating visual assessments. This study demonstrated that loss of tongue coating along with fungal overgrowth reflects the coincidence of alterations in the bacterial community and an increased prevalence of decayed teeth, indicating a higher risk of dental caries. The study findings highlight the importance of assessing both dental health status and tongue microbiota in older adults with slight tongue coating.