The gut-lung axis in COPD: immunomodulatory roles of gut microbiota and novel therapeutic strategies

Chronic Obstructive Pulmonary Disease (COPD) is a progressive respiratory disorder characterized by persistent airflow limitation and systemic inflammation, with accumulating evidence implicating gut microbiota dysbiosis as a key modulator of disease pathogenesis via the gut-lung axis. This review synthesizes current knowledge on the bidirectional communication between the gut and lungs, highlighting how microbial metabolites—particularly short-chain fatty acids (SCFAs), tryptophan derivatives, and bile acids—regulate pulmonary immunity through G-protein-coupled receptors, histone deacetylase inhibition, and aryl hydrocarbon receptor signaling. Dysbiosis-driven disruptions in these pathways exacerbate…