Fine Particulate Matter Perturbs the Pulmonary Microbiota in Broiler Chickens

SIMPLE SUMMARY: Particulate matter (PM) is the most important hazardous pollutant and seriously affects the respiratory tract health of both animals and humans. Nowadays, the development of intensive animal husbandry not only increases PM pollution in the atmospheric environment but also harms the health of animals and ranch workers. The concentration of PM in poultry houses is higher than that for other animals, such as in pig and cow houses. However, there are few studies on the effect of fine particulate matter on pulmonary microbiota in poultry. This study aims to explore the effect of fine particulate matter on pulmonary microbiota in broilers. ABSTRACT: (1) Fine particulate matter (PM(2.5)) seriously affects the respiratory tract health of both animals and humans. Growing evidence indicates that the pulmonary microbiota is involved in the development of respiratory tract health; however, there is still much that is unknown about the specific changes of pulmonary microbiota caused by PM(2.5) in broilers. (2) In this experiment, a total of 48 broilers were randomly divided into a control group and PM-exposure group. The experiment lasted for 21 days. Microbiota, inflammation biomarkers, and histological markers in the lungs were determined. (3) On the last day of the experiment, PM significantly disrupted the structure of lung tissue and induced chronic pulmonary inflammation by increasing IL-6, TNFα, and IFNγ expression and decreasing IL-10 expression. PM exposure significantly altered the α and β diversity of pulmonary microbiota. At the phylum level, PM exposure significantly decreased the Firmicutes abundance and increased the abundance of Actinobacteria and Proteobacteria. At the genus level, PM exposure significantly increased the abundance of Rhodococcus, Achromobacter, Pseudomonas, and Ochrobactrum. We also observed positive associations of the above altered genera with lung TNFα and IFNγ expression. (4) The results suggest that PM perturbs the pulmonary microbiota and induces chronic inflammation, and the pulmonary microbiota possibly contributes to the development of lung inflammation.