1 Department of Biochemistry and Biomedical Sciences.
Ann Am Thorac Soc. 2014 May;11(4):513-21. doi: 10.1513/AnnalsATS.201310-351OC.
The microbial communities inhabiting the upper respiratory tract protect from respiratory infection. The maturity of the immune system is a major influence on the composition of the microbiome and, in youth, the microbiota and immune system are believed to mature in tandem. With age, immune function declines and susceptibility to respiratory infection increases. Whether these changes contribute to the microbial composition of the respiratory tract is unknown.
Our goal was to determine whether the microbes of the upper respiratory tract differ between mid-aged adults (18-40 yr) and the elderly (>65 yr).
Microbiomes of the anterior nares and oropharynx of elderly individuals were evaluated by 16S rRNA gene sequencing. These communities were compared with data on mid-aged adults obtained from the Human Microbiome Project.
The microbiota of the elderly showed no associations with sex, comorbidities, residence, or vaccinations. Comparisons of mid-aged adults and the elderly demonstrated significant differences in the composition of the anterior nares and oropharynx, including a population in the anterior nares of the elderly that more closely resembled the oropharynx than the anterior nares of adults. The elderly oropharyngeal microbiota were characterized by increased abundance of streptococci, specifically, Streptococcus salivarius group species, but not Streptococcus pneumoniae, carriage of which was low (<3% of participants), as demonstrated by PCR (n = 4/123).
Microbial populations of the upper respiratory tract in mid-aged adults and the elderly differ; it is possible that these differences contribute to the increased risk of respiratory infections experienced by the elderly.
上呼吸道寄居的微生物群落可预防呼吸道感染。免疫系统的成熟对上呼吸道微生物组的组成有重大影响，在青年时期，微生物组和免疫系统被认为是同步成熟的。随着年龄的增长，免疫功能下降，呼吸道感染的易感性增加。这些变化是否会导致呼吸道微生物组成的改变尚不清楚。
我们的目标是确定上呼吸道的微生物在中年成年人（18-40 岁）和老年人（>65 岁）之间是否存在差异。
通过 16S rRNA 基因测序评估老年人的前鼻孔和口咽部微生物组。将这些群落与人类微生物组计划中获得的中年成年人的数据进行比较。
老年人的微生物组与性别、合并症、居住地或疫苗接种无关。中年成年人和老年人的比较表明，前鼻孔和口咽部的组成存在显著差异，包括老年人前鼻孔中的一个群体，其与口咽部的相似性大于与成年人前鼻孔的相似性。老年人的口咽微生物组的特征是链球菌的丰度增加，特别是唾液链球菌组的物种，但不包括肺炎链球菌，因为聚合酶链反应（PCR）（n = 4/123）显示其携带率较低（<3%的参与者）。
中年成年人和老年人的上呼吸道微生物种群存在差异；这些差异可能导致老年人呼吸道感染风险增加。
