Division of Pediatric Pulmonary Medicine, New York University School of Medicine, New York, New York.
Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts.
Pediatr Pulmonol. 2018 Sep;53(9):1288-1298. doi: 10.1002/ppul.24115. Epub 2018 Jul 8.
In pediatric patients with chronic cough, respiratory culture techniques commonly yield negative results. Studies using culture-independent methods have found a high relative abundance of oral microbes in the lower airways, suggesting that the topographical continuity, and dynamics of the intraluminal contents of the aerodigestive system likely influence the lower airway microbiota. We hypothesize that in subjects with chronic cough, clinical diagnosis will correlate with distinct microbial signatures detected using culture-independent methods.
We enrolled 36 pediatric subjects with chronic cough in a cross-sectional study. Subjects were categorized into four clinical groups: asthma, bacterial bronchitis, neurologically impaired-orally fed, and neurologically impaired enterally fed. Samples from the aerodigestive tract were obtained through bronchoscopy and upper endoscopy. 16S rRNA gene sequencing compared the microbiota from bronchoalveolar lavage (BAL), tracheal, supraglottic, esophageal, gastric, and duodenal samples.
We observed that the lower airway microbiota of asthma subjects had higher α diversity as compared with the other groups. β diversity analysis of BAL samples revealed significant differences between the groups. Among the taxonomic differences found, most differentially enriched taxa were upper airway organisms such as Rothia, Gemellaceae (u.g. or uncharacterized genus), and Granulicatella in asthma, Prevotella in bacterial bronchitis, and Veillonella in neurologically impaired orally fed subjects. Greater dissimilarity between the upper airway and lower airway microbiota was associated with increased neutrophilic airway inflammation.
Distinct dysbiotic signatures can be identified in the lower airway microbiota of pediatric subjects with chronic cough that relates to the degree and type of inflammation.
在患有慢性咳嗽的儿科患者中，呼吸培养技术通常产生阴性结果。使用非培养方法的研究发现，下呼吸道中口腔微生物的相对丰度较高，这表明呼吸道和消化道管腔内内容物的拓扑连续性和动态变化可能会影响下呼吸道微生物组。我们假设，在慢性咳嗽的患者中，临床诊断将与使用非培养方法检测到的独特微生物特征相关。
我们在一项横断面研究中招募了 36 名患有慢性咳嗽的儿科患者。将患者分为 4 个临床组：哮喘、细菌性支气管炎、神经受损-经口喂养和神经受损-肠内喂养。通过支气管镜和上消化道内镜获取呼吸道和消化道的样本。16S rRNA 基因测序比较了支气管肺泡灌洗液（BAL）、气管、声门上、食管、胃和十二指肠样本的微生物群。
我们观察到哮喘患者的下呼吸道微生物群的 α 多样性高于其他组。BAL 样本的 β 多样性分析显示各组之间存在显著差异。在发现的分类差异中，最丰富的差异丰度的分类群是上呼吸道生物体，如 Rothia、Gemellaceae（u.g. 或未分类属）和 Granulicatella 在哮喘中，Prevotella 在细菌性支气管炎中，以及神经受损-经口喂养的患者中的 Veillonella。上呼吸道和下呼吸道微生物群之间的差异越大，与中性粒细胞性气道炎症的增加有关。
在患有慢性咳嗽的儿科患者的下呼吸道微生物群中可以识别出独特的失调特征，这些特征与炎症的程度和类型有关。
