Research from the University of California, Riverside suggests that inhaling agricultural dust may have significant implications for gut health among workers in animal agriculture.
The study led by Prof. Declan McCole from UCR’s School of Medicine builds on earlier research linking hog farm dust to airway inflammation. The new findings published in the Journal of Applied Toxicology show that inhaling this dust also disrupts the gut microbiome and impairs intestinal function, leading to increased intestinal permeability or "leaky gut." This condition is linked to various chronic diseases including inflammatory bowel disease, celiac disease, and type 1 diabetes.
Journal of Applied Toxicology"Exposure to swine farm dust containing high levels of bacteria and endotoxins led to both airway inflammation and increased passage of bacterial products from the gut into the bloodstream in our mouse models," said Meli'sa Crawford, the study’s first author. "The most notable finding was the impact on gut microbiome and metabolism."
For three weeks, mice were exposed intranasally to hog dust extract, which resulted in a significant reduction of beneficial bacterial species such as Akkermansia muciniphila, Clostridium sp. ASF356, and Lachnospiraceae bacterium.
The research also identified decreased levels of crucial gut compounds like riboflavin, nicotinic acid, inosine, and leucine—important for energy metabolism, immune regulation, and maintaining gut barrier integrity.
"While prior studies have focused on the respiratory effects of farm dust, our findings demonstrate that inhaled pollutants can have widespread systemic impacts," McCole noted. "This highlights the importance of considering the gut-lung axis when evaluating health risks from bioaerosol exposure in agriculture."
The study strengthens evidence that pollution from concentrated animal feeding operations affects multiple organ systems.
"Agricultural dust poses a complex threat to farmworkers, containing fine particulate matter and resistant bacteria," McCole explained. "Our earlier findings showed inhaled hog dust extract causes neutrophilic lung inflammation; now we show its link to intestinal barrier dysfunction and microbial imbalance, emphasizing the need for better workplace protections for agricultural workers."
Funding came from the National Institutes of Health, University of California Davis-Western Center for Agricultural Health and Safety, and UC Presidential Postdoctoral Fellowship Program. Meli'sa Crawford is now an assistant professor in the Department of Animal Sciences at Rutgers University.
The research paper title is "Respiratory Exposure to Agriculture Dust Extract Alters Gut Commensal Species and Key Metabolites in Mice."