A recent study published in mSphere highlights the impact of environmental dust on the lung microbiome, revealing that substances like dust from the drying Salton Sea in California can adversely affect lung health. While much is known about gut microbiomes, the lung microbiome remains less understood, despite its potential benefits to health.
Researchers from the University of California, Riverside (UC Riverside) discovered that exposure to dust from the Salton Sea not only irritates lung microbes but also modifies immune responses. The study”s lead author, Mia Maltz, emphasized the significant changes caused by dust, stating, “Even Salton Sea dust filtered to remove live bacteria or fungi is altering what microbes survive in the lungs. It is causing deep changes to our internal environment.”
The researchers had initially suspected that environmental factors might be linked to declining lung health. During fieldwork to collect dust samples, they experienced discomfort in their lungs, echoing concerns from local residents about the relationship between their environment and respiratory illnesses.
During the experiment, the team observed a notable increase in the populations of Pseudomonas and Staphylococcus bacteria in mice exposed to the dust, both of which are associated with lung inflammation. The dust samples that had the most pronounced effects were found to contain bacteria that release lipopolysaccharides (LPS), which can trigger immune responses. Maltz noted, “We think microbial products like LPS are part of what”s causing the inflammation. It”s like breathing in a chemical fingerprint of dead bacteria.”
Mice exposed to the most potent dust samples exhibited a significant increase in immune cells related to fighting infections, suggesting a strong immune response to the harmful exposure. In contrast, the control group of mice that inhaled clean air showed much lower levels of these immune cells.
The findings challenge previous understandings of lung health, particularly since the mice used in the study had no pre-existing conditions. Co-author Aronson remarked, “We”ve seen these kinds of microbial shifts in people with cystic fibrosis or infections. But these mice had no pre-existing conditions. This was a clean slate, and it still happened.”
As the Salton Sea continues to diminish, releasing more hazardous dust, the researchers express concern over the long-term health implications for local communities. David Lo, a distinguished professor of biomedical sciences at UC Riverside, warned that ongoing exposure to this dust could lead to chronic lung issues, including asthma. “Breathing in the dust over time may have chronic impacts in the lung, and these studies on the potential for altering the lung microbiome are an important first step in identifying factors that could lead to asthma and other chronic diseases,” Lo stated.
The research team is also considering the implications of other environmental exposures, such as wildfire smoke, cigarette smoke, and vehicle exhaust, on the lung microbiome. Maltz remarked, “We”ve only just begun to understand how dust exposure changes the lung microbiome. We don”t yet know how long the changes last, or whether they”re reversible. That”s another big question.”
