| Objective: To study the difference of respiratory bacteria microbiome between patients with Cough Variant Asthma(CVA)and typical chronic asthma.To explore the difference of respiratory bacteria microbiome between acute and chronic asthma.Methods:(1)From October 2020 to November 2021,21 patients with typical acute onset asthma,8 patients with typical chronic duration asthma and 10 patients with CVA as well as 8 healthy volunteers were recruited from the inpatient department of Respiratory and Critical Care of The Third Affiliated Hospital of Zunyi Medical University.General clinical data of the volunteers were recorded in detail.(2)Upper and lower respiratory tract samples were collected by oropharyngeal swabs and induced sputum;Bacterial microbiome of oropharyngeal swabs and induced sputum were detected by 16 S r RNA gene sequencing and statistically described.(3)Enzyme-Linked Immunosorbent Assay(ELISA)was used to detect Interleukin-5(IL-5)and Interleukin-17(IL-17)in serum and sputum supernatant.And Spearman correlation analysis was used to analyze the correlation between clinical data,serum and sputum supernatant concentrations of IL-5 and IL-17 and respiratory tract bacterial flora.Results:(1)Through the longitudinal analysis of the respiratory microbiome of the subjects in each group,it was found that the distribution of the main flora in the upper and lower respiratory tract was different between healthy people and CVA patients,but the distribution of the main flora in the upper and lower respiratory tract of typical asthma was basically the same.The bacterial flora richness and diversity of lower respiratory tract in patients with CVA and chronic asthma were higher than that in patients with upper respiratory tract,and the differences were statistically significant(P<0.05),while there were no significant differences in the bacterial flora richness and diversity of upper and lower respiratory tract in patients with acute asthma(P>0.05).Different from CVA patients,the abundance of Fusobacteriota in the upper respiratory tract of typical asthma patients was greater than that of the lower respiratory tract.The differences were statistically significant(P<0.05).(2)Through cross-sectional analysis of respiratory bacterial microbiome of the subjects,it was found that there was no significant difference in the richness and diversity of lower respiratory bacterial community between CVA patients and typical asthma patients(P>0.05).The abundance of Velonococcus in lower respiratory tract of patients with acute asthma was higher than that of patients with chronic asthma,Myxococcata and MBNT15 were only present in lower respiratory tract of patients with chronic asthma,the differences were statistically significant(P<0.05).In the patients with untreated lower respiratory tract during acute attack of asthma,the bacterial community diversity of Bacteroidota and Prevotella was greater than that of third-generation cephalosporin,while the abundance of Abiotrophia,Rhodococcus and Delfteia was lower than that of third-generation cephalosporin.The differences were statistically significant(P<0.05).(3)The levels of FEV1 and FEV1/FVC in typical asthma patients were lower than those in CVA patients,and the concentration of IL-5 in serum was higher than that in CVA patients,while the concentration of IL-17 in sputum supernatant was lower than that in CVA patients.Compared with patients with typical chronic duration of Asthma,patients with acute attack have longer course of disease,lung often accompanied by Asthma,lower Asthma Control Test(ACT)score,lower PEF and PEF% value in lung function,and higher concentration of IL-17 in serum and sputum supernatant.The concentration of IL-5in serum and sputum supernatant of patients treated with third-generation cephalosporin was lower than that of untreated patients with acute asthma.The differences were statistically significant(P<0.05).In addition,Body Mass Index(BMI),lung function,ACT score,il-5 and IL-17 in serum and sputum superclear of asthmatic patients were correlated with one or more kinds of respiratory tract flora to varying degrees.Conclusion:(1)The characteristics of microbe distribution in upper and lower respiratory tract of patients with cough variant asthma are different from typical asthma.Regular monitoring of the change of respiratory microflora characteristics may be helpful for the early identification,diagnosis and treatment of patients with late transformation of typical asthma.(2)Changes in the abundance of certain bacterial flora in the respiratory tract of asthmatic patients may be one of the causes of acute attacks.(3)Similar to lung function,inflammatory factors,ACT score and other asthma control indicators,changes in respiratory bacterial microbiome may serve as a new important indicator for asthma control and monitoring. |
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