The role of high-fiber diets in modulating the gut-lung axis and asthmatic inflammation.

The gut microbiota is a key regulator of human health and disease, exhibiting considerable functional diversity. High-fiber diets are known to profoundly reshape the gut microbial composition and its metabolic output, notably enhancing the production of short-chain fatty acids (SCFAs). These SCFAs mediate communication along the gut-lung axis through multiple mechanisms, including epigenetic modifications, receptor-mediated signaling, and immunomodulation. Consequently, SCFAs promote regulatory T-cell expansion, restore Th1/Th2 balance, and alleviate airway inflammation in asthma. While clinical observations suggest that high-fiber intake can improve asthma symptoms and lung function, its long-term efficacy and generalizability across diverse populations require further investigation. Elucidating the mechanisms of microbial metabolites within the gut-lung axis through multi-omics integration represents a promising option for developing targeted nutritional interventions, particularly for pediatric and treatment-resistant asthma.