The pulmonary bacterial and fungal microbiota in sarcoidosis patients

Abstract

<b>Background:</b> The aetiology of sarcoidosis is unknown. A modified microbiome could be involved in the pathogenesis. <b>Aim:</b> To investigate the lower airways microbiota in sarcoidosis patients compared to healthy controls. <b>Methods:</b> We collected protected bronchoalveolar lavage (PBAL) in 35 sarcoidosis patients from the MicroILD study and 35 healthy controls from the MicroCOPD study. The V3V4 region of the 16S rDNA gene was sequenced for bacterial detection and the ITS1 region for fungal. We used QIIME 2 and the R package Decontam for bioinformatic analyses. <b>Results:</b> The bacterial microbiota in sarcoidosis had significantly lower Faiths alpha diversity compared to controls (p=0.03) and the beta diversity differed between study groups (unweighted UniFrac, p=0.02). There were no statistically significant taxonomic differences in the bacterial microbiota at the phylum and genus levels as assessed by ANCOM-BC between groups. For the fungal microbiota the beta diversity differed significantly between sarcoidosis and controls assessed by Jaccard (p=0.03) and Bray-Curtis (p=0.03). There were several taxonomic differences in the fungal microbiota between study groups at class level (Figure 1). <b>Conclusions:</b> The bacterial and fungal microbiota differed in sarcoidosis patients compared to healthy controls.