Multi-omic Landscape of Airway Microbe-Host Interactions in Chronic Obstructive Pulmonary Disease

The mechanistic role of the airway microbiome in chronic obstructive pulmonary disease (COPD) remains largely unexplored. We present a landscape of airway microbe-host interactions in COPD by an in-depth profiling of sputum metagenome, metabolome, host transcriptome and proteome from 99 COPD patients and 36 healthy individuals. Multi-omic data were integrated using a sequential mediation analysis, to assess in silico associations of the microbiome with neutrophilic or eosinophilic inflammation, two primary COPD inflammatory endotypes, mediated through microbial metabolic interaction with host gene expression. Mechanistic links of microbiome-metabolite-host interaction were identified leveraging microbial genetic information and established metabolite-human gene pairs. The strongest link for neutrophil-predominant COPD was altered tryptophan metabolism driven by airway lactobacilli resulting in reduced indole-3-acetic acid (IAA), which was in turn linked to perturbed host IL-22 signaling and epithelial cell apoptosis pathways. In vivo and in vitro studies showed that airway microbiome-derived IAA mitigates neutrophilic inflammation, apoptosis, emphysema, and lung function decline, via IL-22-mediated macrophage-epithelial cell crosstalk. Intranasal inoculation of two airway lactobacilli restored IAA and recapitulated its protective effects in mice. These findings provide the rationale for therapeutically targeting microbe-host interaction in COPD.

Linked studies:
UPLC-MS/MS assays of original cohort human samples are reported in this study.
UPLC-MS/MS assays of more recent cohort human samples are reported in MTBLS5423.
UPLC-MS/MS assays of more recent murine samples are reported in MTBLS6894.