Enrichment of the lung microbiome with oral taxa is associated with lung inflammation of a Th17 phenotype

LN Segal, JC Clemente, JCJ Tsay, SB Koralov… - Nature …, 2016 - nature.com
LN Segal, JC Clemente, JCJ Tsay, SB Koralov, BC Keller, BG Wu, Y Li, N Shen, E Ghedin
Nature microbiology, 2016nature.com
Microaspiration is a common phenomenon in healthy subjects, but its frequency is increased
in chronic inflammatory airway diseases, and its role in inflammatory and immune
phenotypes is unclear. We have previously demonstrated that acellular bronchoalveolar
lavage samples from half of the healthy people examined are enriched with oral taxa (here
called pneumotype SPT) and this finding is associated with increased numbers of
lymphocytes and neutrophils in bronchoalveolar lavage. Here, we have characterized the …
Abstract
Microaspiration is a common phenomenon in healthy subjects, but its frequency is increased in chronic inflammatory airway diseases, and its role in inflammatory and immune phenotypes is unclear. We have previously demonstrated that acellular bronchoalveolar lavage samples from half of the healthy people examined are enriched with oral taxa (here called pneumotype SPT) and this finding is associated with increased numbers of lymphocytes and neutrophils in bronchoalveolar lavage. Here, we have characterized the inflammatory phenotype using a multi-omic approach. By evaluating both upper airway and acellular bronchoalveolar lavage samples from 49 subjects from three cohorts without known pulmonary disease, we observed that pneumotype SPT was associated with a distinct metabolic profile, enhanced expression of inflammatory cytokines, a pro-inflammatory phenotype characterized by elevated Th-17 lymphocytes and, conversely, a blunted alveolar macrophage TLR4 response. The cellular immune responses observed in the lower airways of humans with pneumotype SPT indicate a role for the aspiration-derived microbiota in regulating the basal inflammatory status at the pulmonary mucosal surface.
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