Distinct Basal Gut Microbiota Profiles Are Associated with Strain-Specific Lung Responses to Aspergillus fumigatus

Antibiotic-associated gut dysbiosis affects lung health and contributes to disease progression, but the individual response to antibiotics, which leads to host-specific reactions to the same respiratory insult, is not fully understood.

Before infection with Aspergillus fumigatus, Albino Oxford (AO) and Dark Agouti (DA) rats received a mixture of antibiotics with poor systemic absorption to induce microbial perturbation only in the gut, and lung and gut tissue and colonic contents were analyzed.

Treatment with antibiotics induced gut inflammation in both rat strains, which was more pronounced in AO rats, and a disturbance in lung immunity was observed only in DA rats. Antibiotic-associated gut microbiota disturbance revealed rat strain-specific bacterial profiles (increased Gammaproteobacteria in DA and decreased Coriobacteriia in AO rats). Although gut dysbiosis increased the risk of lung A. fumigatus infection in both rat strains, a higher fungal burden was detected in the lungs of AO rats, whereas lymph node cell activation and lung tissue inflammation were observed in DA rats.

Rat strain differences in response to antibiotic- and/or infection-induced gut dysbiosis suggest that basal gut microbiota may influence the lung immune response during A. fumigatus disease, highlighting the importance of the interplay of genotype-specific host gut microbial community with the environmental constraints in shaping individual immune makeup.