Gut-lung axis

The gut-lung axis is a bidirectional communication network between the gastrointestinal tract and the respiratory system, primarily mediated by the gut microbiota and its metabolic products [1, 3]. This axis facilitates the systemic transport of microbial metabolites, such as short-chain fatty acids (SCFAs) and tryptophan derivatives, as well as the trafficking of immune cells like regulatory T cells (Tregs) and Th17 cells between the gut and lungs [5, 6]. These components play a critical role in maintaining pulmonary immune homeostasis and protecting against inflammatory and infectious diseases [1, 11]. Dysbiosis of the gut microbiota is linked to the pathogenesis of various respiratory conditions, including asthma, chronic obstructive pulmonary disease (COPD), and lung cancer, by promoting systemic inflammation and impairing lung barrier function [2, 5, 7]. Therapeutic strategies targeting the gut-lung axis, such as probiotics, prebiotics, and fecal microbiota transplantation (FMT), aim to restore microbial balance and modulate immune responses to treat or prevent lung diseases [3, 8]. Furthermore, the axis involves neuro-immune signaling via the vagus nerve, which senses microbial signals in the gut to modulate airway tone and immune responses [11]. Disruptions in this crosstalk, often caused by antibiotics or dietary changes, can exacerbate lung injury and increase susceptibility to infections like COVID-19 [6, 9]. Emerging research also highlights the role of the gut-lung axis in the efficacy of cancer immunotherapies, where gut microbial diversity correlates with better responses to immune checkpoint inhibitors in lung cancer patients [7, 10].

Other names

Microbiota-gut-lung axisGut-lung crosstalkMGLA

Modulation of gut microbiota composition, production of microbial metabolites (e.g., short-chain fatty acids, tryptophan derivatives), and regulation of immune cell trafficking (e.g., regulatory T cells, Th17 cells) between the gut and lungs.