Chronic Exposure to Ambient Particulate Matter Induces Gut Microbial Dysbiosis in a Rat COPD Model

Abstract Background The role of the gut microbiota in the pathogenesis of chronic obstructive pulmonary disease following exposure to ambient particulate matter is largely unknown. We hypothesized that exposure alters gut microbial composition and metabolites and is involved in the pathogenesis of chronic obstructive pulmonary disease. Methods Fifty-four male Sprague-Dawley rats were exposed to clean air, biomass fuel, or motor vehicle exhaust for 4, 12, and 24 weeks. Lung tissue was assessed histologically and gut microbial composition was assessed by 16S rRNA pyrosequencing. Serum lipopolysaccharide levels were measured and short-chain fatty acids in colon contents were quantified. Results After a 24-week exposure to particulate matter, rats exhibited pulmonary inflammation and pathological changes characteristic of chronic obstructive pulmonary disease. The gut microbiome was characterized by decreased microbial richness and diversity, distinct overall microbial composition, lower levels of short-chain fatty acids, and higher serum lipopolysaccharide. Conclusion Chronic exposure to ambient particulate matter induces gut microbial dysbiosis and metabolite shifts in a rat model of chronic obstructive pulmonary disease.