Human Sputum Microbiome Composition and Sputum Inflammatory Cell Profiles Are Altered with Controlled Wood Smoke Exposure as a Model for Wildfire Smoke.
Catalina Cobos-Uribe, Radhika Dhingra, Martha A Almond, Neil E Alexis, David B Peden, Jeffrey Roach, Meghan E Rebuli
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引用次数: 0
Abstract
Rationale: Wood smoke exposure is increasing worldwide due to the rise in wildfire events. Various studies have associated exposure to wildfire-derived smoke with adverse respiratory conditions. However, the mechanism by which this occurs is unknown. Previous studies using wood smoke as a model of wildfire smoke have focused on the respiratory immune response and have reported increased neutrophil percentage and cytokine production in airway samples. The effect of wood smoke on the respiratory microbiome, however, has not been examined.
Methods: Healthy volunteers (N=54) were subjected to controlled wood smoke exposure (500 µg/m3) for two hours, and induced sputum samples were collected and processed for microbiome analysis, immune mediators, and cell differentials at baseline, six- and 24-hours post-exposure. A negative binomial mixed model analysis examined associations between microbiome components and inflammatory cells in sputum.
Main results: Following wood smoke exposure, while sputum microbiome diversity remained unchanged, the microbiome composition was altered, particularly the abundance of several low-abundance bacteria, including Fretibacterium and Selenomonas, indicating that this inhalational exposure can alter the composition of the sputum microbiome. Additionally, a significant decrease in macrophage cells was observed at 24 hours without a significant change in neutrophils. We further found small but significant associations between different taxa and macrophages (per mg of sputum), including a negative association with Fretibacterium.
Conclusions: Together, these findings demonstrate that inhalational wood smoke exposure can modify several low-abundance bacteria within the respiratory microbiome and that these changes are associated with sputum inflammatory cell alterations, providing insights for future studies to focus on respiratory innate immune host-microbiome crosstalk in the context of environmental exposures.
期刊介绍：
The American Journal of Respiratory and Critical Care Medicine focuses on human biology and disease, as well as animal studies that contribute to the understanding of pathophysiology and treatment of diseases that affect the respiratory system and critically ill patients. Papers that are solely or predominantly based in cell and molecular biology are published in the companion journal, the American Journal of Respiratory Cell and Molecular Biology. The Journal also seeks to publish clinical trials and outstanding review articles on areas of interest in several forms. The State-of-the-Art review is a treatise usually covering a broad field that brings bench research to the bedside. Shorter reviews are published as Critical Care Perspectives or Pulmonary Perspectives. These are generally focused on a more limited area and advance a concerted opinion about care for a specific process. Concise Clinical Reviews provide an evidence-based synthesis of the literature pertaining to topics of fundamental importance to the practice of pulmonary, critical care, and sleep medicine. Images providing advances or unusual contributions to the field are published as Images in Pulmonary, Critical Care, Sleep Medicine and the Sciences.
A recent trend and future direction of the Journal has been to include debates of a topical nature on issues of importance in pulmonary and critical care medicine and to the membership of the American Thoracic Society. Other recent changes have included encompassing works from the field of critical care medicine and the extension of the editorial governing of journal policy to colleagues outside of the United States of America. The focus and direction of the Journal is to establish an international forum for state-of-the-art respiratory and critical care medicine.
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