The murine lung microbiome is dysbalanced by the human pathogenic fungusAspergillus fumigatusresulting in enrichment of anaerobic bacteria

Abstract

SummaryHere, we report significant changes in the composition of the lung microbiome and metabolome of mice under immune suppression, infection of immunosuppressed mice with virulent and avirulent strains of the clinically important human-pathogenic fungusAspergillus fumigatus, and treatment with the clinically used antifungal drug voriconazole. Our data also indicate the important role of the gut microbiome for the lung homeostasis mediated by the plasma metabolome. In the lung microbiome, infection byA. fumigatusled to a significant increase of anaerobic bacteria, most prominently ofLigilactobacillus murinus,which was confirmed by the isolation of live bacteria from the murine lower respiratory tract.In vitro,L. murinusis tolerated and even internalized by alveolar epithelial cells. Co-cultivation ofL. murinusandA. fumigatusled to a reduction in oxygen concentration accompanied by an increase ofL. murinuscells suggesting thatA. fumigatusestablishes a microaerophilic niche, thereby promoting growth of anaerobic bacteria.