A study published in the journal Gut reveals that the gut microbiome plays a significant role in the development of chronic obstructive pulmonary disease (COPD), and that faecal microbial transfer (FMT) can alleviate key features of the disease. The research, conducted using an in vivo mouse model of cigarette smoke (CS)-induced COPD and FMT, characterized the faecal 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 16 patients with COPD using a randomized, double-blind, placebo-controlled pilot study of inulin supplementation. Results showed that FMT alleviated hallmark features of COPD, including inflammation, alveolar destruction, impaired lung function, gastrointestinal pathology, and systemic immune changes. Protective effects were additive to smoking cessation, and transfer of CS-associated microbiota after antibiotic-induced microbiome depletion was sufficient to increase lung inflammation while suppressing colonic immunity in the absence of CS exposure. Disease features correlated with the relative abundance of certain bacterial families. Proteomics and metabolomics identified downregulation of glucose and starch metabolism in CS-associated microbiota, and supplementation of mice or human patients with complex carbohydrates improved disease outcomes. The study also found that dietary resistant starch alleviated inflammation and emphysema in experimental COPD. Inulin supplementation in human COPD patients reduced symptoms and exacerbations, improving health-related quality of life. The findings suggest that targeting the gut microbiome through FMT and dietary interventions may offer new therapeutic approaches for COPD.A study published in the journal Gut reveals that the gut microbiome plays a significant role in the development of chronic obstructive pulmonary disease (COPD), and that faecal microbial transfer (FMT) can alleviate key features of the disease. The research, conducted using an in vivo mouse model of cigarette smoke (CS)-induced COPD and FMT, characterized the faecal 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 16 patients with COPD using a randomized, double-blind, placebo-controlled pilot study of inulin supplementation. Results showed that FMT alleviated hallmark features of COPD, including inflammation, alveolar destruction, impaired lung function, gastrointestinal pathology, and systemic immune changes. Protective effects were additive to smoking cessation, and transfer of CS-associated microbiota after antibiotic-induced microbiome depletion was sufficient to increase lung inflammation while suppressing colonic immunity in the absence of CS exposure. Disease features correlated with the relative abundance of certain bacterial families. Proteomics and metabolomics identified downregulation of glucose and starch metabolism in CS-associated microbiota, and supplementation of mice or human patients with complex carbohydrates improved disease outcomes. The study also found that dietary resistant starch alleviated inflammation and emphysema in experimental COPD. Inulin supplementation in human COPD patients reduced symptoms and exacerbations, improving health-related quality of life. The findings suggest that targeting the gut microbiome through FMT and dietary interventions may offer new therapeutic approaches for COPD.