The Intriguing Connection Between the Gut and Lung Microbiomes

Abstract

Recent advances in microbiome research have uncovered a dynamic and complex connection between the gut and lungs, known as the gut-lung axis. This bidirectional communication network plays a critical role in modulating immune responses and maintaining respiratory health. Mediated by immune interactions, metabolic byproducts, and microbial communities in both organs, this axis demonstrates how gut-derived signals, such as metabolites and immune modulators, can reach the lung tissue via systemic circulation, influencing respiratory function and disease susceptibility. To explore the implications of this connection, we conducted a systematic review of studies published between 2001 and 2024 (with as much as nearly 60% covering the period 2020-2024), using keywords such as "gut-lung axis", "microbiome", "respiratory disease", and "immune signaling". Studies were selected based on their relevance to gut-lung communication mechanisms, the impact of dysbiosis, and the role of the gut microbiota in respiratory diseases. This review provides a comprehensive overview of the gut-lung microbiome axis, emphasizing its importance in regulating inflammatory and immune responses linked to respiratory health. Understanding this intricate pathway opens new avenues for microbiota-targeted therapeutic strategies, which could offer promising interventions for respiratory diseases like asthma, chronic obstructive pulmonary disease, and even infections. The insights gained through this research underscore the potential of the gut-lung axis as a novel target for preventative and therapeutic approaches in respiratory medicine, with implications for enhancing both gut and lung health.

Keywords: gut–lung axis; microbiome; respiratory diseases.

Figure 1

The gut–lung axis: interconnected immune regulation. The gastrointestinal tract is depicted with its diverse microbial communities producing metabolites that modulate lung immunity. In turn, respiratory infections or inflammation can disrupt the gut microbiota, leading to dysbiosis. Key components like immune cells (macrophages, dendritic cells) and inflammatory mediators (cytokines, chemokines) are messengers facilitating this bidirectional interaction. Imbalances in the gut microbiome may contribute to respiratory diseases such as asthma, inflammatory bowel disease, and lung infections.