Multi-omics analyses of airway host-microbe interactions in chronic obstructive pulmonary disease identify potential therapeutic interventions.

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 through an in-depth profiling of the sputum metagenome, metabolome, host transcriptome and proteome from 99 patients with COPD and 36 healthy individuals in China. Multi-omics data were integrated using sequential mediation analysis, to assess in silico associations of the microbiome with two primary COPD inflammatory endotypes, neutrophilic or eosinophilic inflammation, mediated through microbial metabolic interaction with host gene expression. Hypotheses of microbiome-metabolite-host interaction were identified by leveraging microbial genetic information and established metabolite-human gene pairs. A prominent hypothesis for neutrophil-predominant COPD was altered tryptophan metabolism in airway lactobacilli associated with reduced indole-3-acetic acid (IAA), which was in turn linked to perturbed host interleukin-22 signalling 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 macrophage-epithelial cell cross-talk mediated by interleukin-22. 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.

Effects of two types of equal-intensity inspiratory muscle training in stable patients with chronic obstructive pulmonary disease: A randomised controlled trial.

PURPOSE: We conducted a randomised controlled trial to assess the effects of daily breathing pattern changes to stable patients with COPD excluding the confounding factors of inspiratory muscle mobilization, by ensuring the load intensities of two inspiratory training devices were equal. PATIENTS AND METHODS: Sixty patients with COPD were randomised to three groups: resistive-IMT group (T-IMT, 21 patients), threshold-IMT (R-IMT, 19 patients), and a control group (20 patients). Inspiratory load intensity for both methods was set at 60% of maximal inspiratory pressure (MIP), a measure of inspiratory muscle strength, which, along with health-related quality of life (HRQoL), degree of dyspnoea, and exercise capacity, were conducted before and after 8 weeks of daily IMT. RESULTS: At 8 weeks, there was no significantly difference of MIP between the R- and T-IMT groups (P > 0.05). Chronic Respiratory Disease Questionnaire and Transition Dyspnea Index scores improved significantly after each training program compared with controls (P < 0.05), and R-IMT was significant better (P < 0.05). R-IMT was better than T-IMT in performance of exercise (P < 0.05). CONCLUSIONS: In summary, in clinically stable patients with COPD, 8 weeks of R-IMT was superior to 8 weeks of equal-intensity T-IMT in improving HRQoL, degree of dyspnoea, and exercise capacity.