Fecal microbial transfer and complex carbohydrates mediate protection against COPD

Abstract

ABSTRACTObjectiveChronic obstructive pulmonary disease (COPD) is a major cause of global illness and death, most commonly caused by cigarette smoke. The mechanisms of pathogenesis remain poorly understood, limiting the development of effective therapies. The gastrointestinal microbiome has been implicated in chronic lung diseasesviathe gut-lung axis, but its role is unclear.DesignUsing anin vivomouse model of cigarette smoke-induced COPD and fecal microbial transfer (FMT), we characterized the fecal microbiota using metagenomics, proteomics and metabolomics. Findings were correlated with airway and systemic inflammation, lung and gut histopathology, and lung function. Complex carbohydrates were assessed in mice using a high resistant starch diet, and in sixteen COPD patients using a randomized, double-blind, placebo-controlled pilot study of inulin supplementation.ResultsFMT alleviated hallmark features of COPD (inflammation, alveolar destruction, impaired lung function), gastrointestinal pathology and systemic immune changes. Protective effects were additive to smoking cessation. Disease features correlated with the relative abundance ofMuribaculaceae, DesulfovibrionaceaeandLachnospiraceaefamily members. Proteomics and metabolomics identified downregulation of glucose and starch metabolism in cigarette smoke-associated microbiota, and supplementation of mice or human patients with complex carbohydrates improved disease outcomes.ConclusionThe gut microbiome contributes to COPD pathogenesis and can be targeted therapeutically.What is already known on this topicChanges in gut microbiota are associated with COPD but the underlying host and microbial mechanisms are unclear, limiting the therapeutic applications.What this study addsMicrobiome composition and metabolism is reproducibly correlated with lung and gastrointestinal pathology in experimental COPD.Microbiome modifying interventions effectively alleviate disease, including protective effects supplementing smoking cessation.Nutritional interventions targeting the microbiome in COPD patients demonstrate efficacy in a small pilot study.How this study might affect research, practice or policyMicrobiome-targeting therapeutics and nutritional interventions may be developed for COPD, including as supplements to smoking cessation.