Impact of occupational exposure on human microbiota Original paper

What was reviewed?

This review summarized how workplace exposures can reshape the adult human microbiome and why those shifts may matter for disease risk. It covered two broad exposure classes: biotic exposures from workplace microbes (for example, animal facilities, farms, and other high-bioaerosol settings) and abiotic exposures such as chemicals, heavy metals, and particulate matter that are often far higher at work than in daily life. The authors also explained why older “single-proxy” measures like endotoxin can miss important biology, because different bacterial endotoxins can push immune responses in opposite directions.

Who was reviewed?

The review drew from human observational studies, time-series workplace sampling studies, and supportive animal-model work rather than a single clinical cohort. It highlighted workers with animal contact (livestock workers, animal care workers, poultry-related work), military personnel with complex chemical exposures, and populations or models exposed to heavy metals and air pollution. Across these studies, the authors considered multiple body sites, especially the nasal passages, skin, oral cavity, lungs, and gut, because different occupational exposures can preferentially affect different microbial communities.

What were the most important findings?

The review emphasized that occupational environments can measurably alter the adult microbiome through both colonization and exposure-driven selection. Animal-associated work can shift the nasal and skin microbiome toward organisms found in the work environment, including strain-level signals such as livestock-associated MRSA colonization in some worker groups. The authors also highlighted evidence that certain military-related chemical mixtures and particulate matter exposures can disturb the gut microbiome and increase gut permeability in model systems, suggesting a gut–immune–lung link that could plausibly contribute to respiratory disease risk. For heavy metals and particles, the review described a consistent theme: these exposures can change gut microbial composition and function, and the microbiome may also modify how the host responds to toxins, making microbiome changes both a target and a mediator of exposure effects.

What are the greatest implications of this review?

For clinicians, the review supports a practical shift in thinking: exposure reduction may not fully reverse disease risk if the exposure already pushed the patient’s microbiome into a more pro-inflammatory or dysbiotic state. This matters for respiratory and systemic conditions where work exposures are intense and repeated, because microbiome changes can persist, interact with immune tone, and influence barrier integrity. The review also implies that occupational history can become clinically actionable microbiome context, especially when symptoms persist after workplace removal, and it highlights an evidence gap that clinicians should note: few studies directly link workplace-driven microbiome changes to hard clinical endpoints, so this remains a key area for future translational research.