Supplemental Digital Content is available in the text. Alteration in microbiota composition of respiratory tract has been reported in the progression of many chronic lung diseases, yet, the correlation and causal link between respiratory tract microbiota and the disease development of pulmonary hypertension (PH) remain largely unknown. This study aims to define and compare the respiratory microbiota composition in pharyngeal swab samples between patients with PH and reference subjects. A total of 118 patients with PH and 79 reference subjects were recruited, and the pharyngeal swab samples were collected to sequence the 16S ribosomal RNA (16S rRNA) V3-V4 region of respiratory microbiome. The relative abundances in patients with PH were profoundly different from reference subjects. The Ace and Sobs indexes indicated that the microbiota richness of pharynx value is significantly higher; while the community diversity value is markedly lower in patients with PH, comparing to those of the reference subjects. The microbiota on pharynx showed a different profile between the 2 groups by principal component analysis. The linear discriminant analysis effect size also revealed a significantly higher proportion of Streptococcus, Lautropia, and Ralstonia in patients with PH than reference subjects. The linear discriminant analysis effect size output, which represents the microbial gene functions, suggest genes related to bacterial invasion of epithelial cells, bacterial toxins were enhanced, while genes related to energy metabolism, protein digestion and absorption, and cell division pathways were attenuated in patients with PH versus reference subjects. In summary, our study reports the first systematic definition and divergent profile of the upper respiratory tract microbiota between patients with PH and reference subjects.

中文翻译：

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肺动脉高压患者气道微生物群组成的改变

补充数字内容在文本中可用。在许多慢性肺病的进展中已经报道了呼吸道微生物群组成的改变，然而，呼吸道微生物群与肺动脉高压（PH）的疾病发展之间的相关性和因果关系仍然很大程度上未知。本研究旨在定义和比较 PH 患者和参考受试者咽拭子样本中的呼吸道微生物群组成。共招募了 118 名 PH 患者和 79 名参考受试者，收集咽拭子样本对呼吸道微生物组的 16S 核糖体 RNA（16S rRNA）V3-V4 区进行测序。PH 患者的相对丰度与参考受试者有很大不同。Ace和Sobs指标表明咽部微生物群丰富度值显着较高；而与参考受试者相比，PH患者的社区多样性值明显较低。通过主成分分析，咽部微生物群在两组之间显示出不同的特征。线性判别分析效应大小还显示，PH 患者中链球菌、劳托氏菌和拉尔斯顿菌的比例显着高于参考受试者。线性判别分析效应大小输出，代表微生物基因功能，提示与细菌侵入上皮细胞、细菌毒素相关的基因，而与能量代谢、蛋白质消化和吸收相关的基因、与参考受试者相比，PH 患者的细胞分裂途径减弱。总之，我们的研究报告了 PH 患者和参考受试者之间上呼吸道微生物群的第一个系统定义和不同特征。