Plant-Derived Probiotics From Fermented Foods: Current Evidence on Antiviral Mechanisms and Gut–Lung Axis Modulation

Abstract

Respiratory viral infections represent a major global public health threat, causing widespread morbidity, mortality, and socioeconomic disruption, while probiotics have emerged as promising candidates for enhancing host immunity and combating infectious diseases. Plant-derived probiotics, mainly sourced from fermented plant foods, exhibit potent antiviral effects against respiratory viruses by modulating innate and adaptive immunity, secreting antiviral metabolites, and regulating gut–lung axis crosstalk. This review comprehensively summarizes the antiviral mechanisms of plant-derived probiotics against respiratory viruses and their advantages over dairy-derived counterparts while discussing the current status and future development trends of these probiotics. Plant-fermented foods are the main natural sources of these probiotics. Their processing requires optimized fermentation, stability and sensory quality, while translation depends on standardized strains, defined mechanisms, advanced delivery, and large-scale clinical trials.