New Study Reveals How Dust Harms Lung Microbiome Health

Research has uncovered that dust from the evaporating Salton Sea in California can have detrimental effects on the lung microbiome, highlighting a previously overlooked area of health science. A recent study published in the journal mSphere by scientists at the University of California, Riverside (UC Riverside) indicates that exposure to this specific dust can alter immune responses in the lungs.

While considerable knowledge exists about the gut microbiome, understanding of the lung microbiome remains limited. Despite this, researchers believe it plays a crucial role in overall health. The UC Riverside team has established that environmental factors, particularly harmful dust, can adversely affect lung microbiome health, which was previously thought to be influenced mainly by genetic factors or bacterial infections.

During the study, the researchers exposed laboratory mice to dust samples collected from the Salton Sea and observed significant changes. Mia Maltz, a mycologist at UC Riverside and the lead author of the study, stated, “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’ fieldwork led them to suspect that the local environment was linked to respiratory issues. Talyssa Topacio, a graduate student and co-first author of the study, described the conditions during their sample collection, noting, “Salton Sea residents have ongoing suspicions that the environment is linked to respiratory illness, and our lab has definitely felt the effects of the heat, dustiness, and pungent air while out there on field work.”

Analysis of the data revealed a spike in populations of Pseudomonas and Staphylococcus bacteria in the exposed mice, both known to cause lung inflammation. The dust samples containing bacteria produced lipopolysaccharides (LPS), molecules that trigger immune responses. Maltz explained, “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 60 percent increase in lung immune cells marked by neutrophils, vital in fighting infections. In contrast, mice breathing neutral air maintained immune cell levels at only 10 to 15 percent.

The findings challenge existing concepts in pulmonology. As David Lo, a distinguished professor of biomedical sciences at UC Riverside, noted, “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 Lake continues to dry, releasing more harmful dust into the environment, the researchers are concerned about the long-term health implications for local populations. They emphasize that chronic exposure to such dust may have lasting impacts on lung health, potentially contributing to conditions like asthma and other chronic diseases.

The research team is also looking into the effects of other environmental pollutants, 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.”

This study sheds light on an important aspect of respiratory health and emphasizes the need for further research into the impact of environmental factors on the lung microbiome. The findings may help pave the way for understanding how to mitigate respiratory illnesses linked to air quality and environmental pollution.