Lower respiratory microbiome in patients with stable bronchiectasis in North and South China

Abstract Objective: To compare microbiome in the lower respiratory tract of patients with stable bronchiectasis in North and South China. Methods: Demographic and Sequencing data were collected from patients who underwent bronchoalveolar lavage fluid macro-genomic sequencing testing between September 2021 to September 2022 at Hainan Hospital of the General Hospital of the People's Liberation Army (Sanya, Hainan, South) and the Eighth Medical Center of the General Hospital of the People's Liberation Army (Haidian, Beijing, North). The patients were grouped according to the clinical test results, and the sequencing data were analyzed twice to compare the microbiome differences among different groups. Results We enrolled 75 patients, 42 in the North and 33 in the South. The number of smokers in the Northern group was higher than that in the Southern group and the FEV1/FVC (%) value was lower than that in the Southern group; otherwise, the groups had no significant differences. The most abundance bacteria in the lower respiratory tract of the Northern group were Pseudomonas aeruginosa, Klebsiella pneumoniae, and Nocardia wilsonii, while the Southern group were H. influenzae, P. aeruginosa, and Prevotella intermedia. According to the severity of the patients with bronchiectasis (BSI), there was also a difference in the abundance of microbiome in the lower respiratory tract in patients with stable bronchiectasis from the North and South. Conclusion The lower respiratory tract microbiome of patients with stable bronchiectasis differed significantly between the North and South in China. The microbiome of the Southern group was more similar to that reported in the international literature, while the Northern group was significantly different from the results of other studies. P. aeruginosa and Klebsiella pneumoniae were most abundant in the Northern group, while H. influenzae and P. aeruginosa were most abundant in the Southern group, These findings can guide antibiotic treatment of exacerbations.