Oral administration of Lacticaseibacillus paracasei attenuates combined allergic rhinitis and asthma syndrome (CARAS) in mice model: Relevance of short-chain fatty acids on gut-airway axis

Probiotics have been shown to have a beneficial effect on allergic diseases. Anti-allergic effect of Lacticaseibacillus paracasei was demonstrated in asthma, however, its effect in combined allergic rhinitis and asthma syndrome (CARAS) is still unclear. This study evaluated the Lacticaseibacillus paracasei (LPc-G110) supplementation in CARAS mice model. BALB/c mice were ovalbumin-sensitized and challenged after being supplemented with LPc-G110. Supplemented animals showed reduced allergic rhinitis signs, eosinophilic infiltration, mucus, extracellular matrix deposition into airway tissues, and lung smooth muscle hypertrophy. LPc-G110 supplementation also reduced eosinophilia, serum levels of allergen-specific IgE, IL-4, IL-13, and IL-5, and favored the production of IFN-γ, IL-10, and short-chain fatty acids. Additionally, LPc-G110 supplementation preserved the gut tissue integrity and epithelial barrier by increasing the tight junction protein ZO-1. Therefore, LPc-G110 improves the gut-airway axis in CARAS by ameliorating inflammatory parameters in both compartments and is a promising candidate for preventing allergic airway diseases.