Stop particulate matter! the balance of the pulmonary microbiota depends on it!

Exposure to suspended particulate matter produced by vehicles may change the pulmonary microbiota and affect immune response in only a few weeks.

Although we already know that the inhalation of suspended particulate matter (SPM)-- mixtures of cigarette smoke, dust, and other pollutants--increases the risk of morbidity and mortality from respiratory diseases, we still don’t know how it impacts the pulmonary microbiota. For four weeks, researchers exposed rats on an almost daily basis to suspended particulate matter from either motor vehicle exhausts or biomass fuel, then compared their pulmonary microbiota to that of control rats breathing clean air. Although they didn’t observe any morphological changes in the lungs, they did, however, notice a variation in the levels of antibodies in the lungs of the rats that inhaled exhaust gas. They also observed a noticeable change in the composition of the respiratory microbiota in the two groups of rats exposed to polluted air, with more bacteria and more varied species. However, the bacteria differed depending on the pollutant. The authors conclude that even short exposure to particulate matter is enough to change the composition of the respiratory microbiota and affect immune response.

Li et al. Exposure to ambient particulate matter alters the microbial composition and induces immune changes in rat lung. Respiratory Research (2017) 18:143