Airway Bacterial And Fungal Community Structure Study Of Chronic Obstructive Diseases

Background:Chronic respiratory diseases,including asthma and chronic obstructive pulmonary disease(COPD),were characterized by flow limitation,expiratory dyspnea,and shortness of breath.The microbial community strcture of respiratory airway in patients of asthma/COPD have their unique characteristics compared with healthy individuals.Previous studies have showed that airway microorganism is associated with asthma and COPD exacerbations and progress.Meanwhile,previous studies reported less number of cases,and seldom researches focused on both bacterial and fungal microbial communities of asthma and COPD.Objectives:To explore the characters of airway microbiome in asthma and COPD.Further explain how microbiome communicate with clinical feathers of disease.Methods:We conducted a cross-sectional study for two years,including Guangzhou Institute of Respiratory Disease and Department of Respiratory Physicians,Nanfang Hospital to recruit qualified volunteers.Participants included 154 cases of asthma,263 cases of COPD,and 33 healthy volunteers.Through the amplification of 16s rRNA V4 fragments and ITS1 fragments,we described the main characteristics of the microbial community structure of the COPD,asthma patients and healthy individuals.Performing random forests model,profoundly comparisons between asthma and COPD,asthma and health,COPD and health were calculated,random forest model was applied to explore the relationship between clinical features and microbiomes as well.In addition,we performed a variety of statistical methods focused on taxon associated with clinical events.Results:The community composition structure of COPD,asthma and health individuals were separated from each other.The random forest models were used to separate asthma and health individuals,the AUC of bacteria and fungi were 97.70 and 98.13;COPD and health individuals were separated with the AUC 96.91 and 99.23 of bacteria and fungi community;COPD and asthma individuals were separated with the AUC 90.33 and 90.86 of bacteria and fungi community respectively.The microbial community structure of acute exacerbation of COPD(AECOPD)and stable COPD groups had significant differences,the AUC of bacteria and fungi were 89.31 and 86.97.Some clinical features and microbial community structure are closely related of COPD,including blood lymphocyte count,Long-acting anticholinergic drugs(LAMA),Long-effect ?2 reactant excitomotor agent+Inhaled corticosteroids(LABA+ ICS),aminophylline and smoke.Species of Pseudomonas,Moraxella,Enterococcus,Candida and Aspergillus played a key role in some clinical features of COPD.The microbial community structure of asthma were not associated with acute exacerbation.But some clinical features were closely related with microbial community structure in asthma,including sputum eosinophil count,asthma control test(ACT)score,and smoke.Species belong to Porphyromonas,Leptotrichia and Candida played an important role in asthma exacerbation and some clinical features.Conclusions:The community composition structure of COPD,asthma and health individuals were separated from each other.We provided microbial data support for the pathogenic mechanisms of diseases such as eosinophils and ACT of asthma,inhaled drugs and inflammation factors of COPD,smoke of asthma/COPD.