Type 2–high asthma is associated with a specific indoor mycobiome and microbiome

Abstract

Background The links between microbial environmental exposures and asthma are well documented, but no study has combined deep-sequencing results from pulmonary and indoor microbiomes of asthmatic patients with spirometry, clinical and endotype parameters. Objective The goal of this study was to investigate the links between indoor microbial exposures and pulmonary microbial communities and to document the role of microbial exposures on inflammatory and clinical outcomes of patients with severe asthma (SA). Methods Fifty-five SA patients from the national COBRA cohort were enrolled for analyzing their indoor microbial flora through the use of electrostatic dust collectors (EDCs). Among these patients, 22 were able to produce sputa during stable or pulmonary exacerbation periods and had complete pairs of EDC and sputum samples, both collected and analysed. We used amplicon targeted metagenomics to compare microbial communities from EDC and sputum samples of patients according to type 2 (T2)-asthma endotypes. Results Compared to patients with T2-low SA, patients with T2-high SA exhibited an increase in bacterial alpha-diversity and a decrease in fungal alpha-diversity of their indoor microbial floras, the latter being significantly correlated with FeNO levels. The beta-diversity of the EDC mycobiome significantly clustered according to T2 endotypes. Moreover, the proportion of fungal taxa in common between sputum and EDC samples was significantly higher when patients exhibited acute exacerbation. Conclusion These results illustrated, for the first time, a potential association between the indoor mycobiome and clinical features of SA patients, which should renew interest in deciphering the interactions between indoor environment, fungi, and host in asthma.

Fractional exhaled nitric oxide (FeNO) in students in Northern Thailand: associations with respiratory symptoms, diagnosed allergy and the home environment

“…We categorized FeNO into three groups; low (<20 ppb), intermediate (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) ppb and high (>35 ppb), as suggested by the American Thoracic Society (ATS) (25). Moreover FeNO was log transformed (10 logarithm) to obtain a normally distributed variable.…”

Reply

“…We thank our colleagues Fu et al 1 for their interest in our work. 2 Our pilot study reported several associations between the indoor microbial exposure, human sputum microbiota and mycobiota, and the occurrence of severe asthma among patients.…”

Asthma in the Precision Medicine Era: Biologics and Probiotics

“…Both bacterial and fungal microbiota signatures were found to correlate with asthma endotypes and clinical features. In recent studies employing the omics approach, decreased airway bacterial and fungal diversity as well as increased relative abundance of Pseudomonas , Trichoderma , Fusarium , Cladosporium and Aspergillus were associated with Th2-high endotype, whereas increased Proteobacteria , Mycosphaerella and Penicillium were clustered with Th2-low type of asthma [ 119 , 165 , 166 ]. The association of microbiome endotypes with asthma endotypes may further contribute to precision asthma endotyping and selection of treatment regimens; however, it has to be taken into consideration that concurrent steroid treatment may change the microbiome and obscure the true association [ 167 ].…”