Pulmonary microbiota affects lung inflammation induced by fine particulate matter from broiler houses

Particulate matter released during the livestock industry not only endangers the respiratory health of animals and workers, but it also pollutes the air environment. Broilers exposed to PM exhibited lung inflammation and changes in the pulmonary microbiome. However, the effect of pulmonary microbiota on PM induced lung inflammation in broilers is less well characterized. In this study, we first established a pulmonary microbiota depleted broiler model using intratracheal instillation antibiotics, and based on it, we explored the effect of pulmonary microbiota on PM induced lung inflammation in broilers. We found that broilers developed a lung inflammatory response after exposure to PM from broiler houses, while depletion of the pulmonary microbiota attenuated the extent of inflammatory damage. We examined the pulmonary microbiome of broilers and observed that PM induced significant changes in the diversity and community of the pulmonary microbiota as well as a significant increase in the relative abundance of Enterococcus cecorum. Furthermore, we demonstrated that PM exposure altered the growth environment of the pulmonary microbiota by treating Enterococcus cecorum with sterile BALF. These results imply that pulmonary microbiota plays a key role in PM induced lung inflammation in broilers.