Efficacy of Lactococcus lactis 11/19-B1 in a Mouse Model of Allergic Rhinitis

Lactococcus lactis (L. lactis) is widely used in fermented foods and has immunomodulatory properties. However, its effects on allergic rhinitis remain unclear.

This study evaluated the efficacy of L. lactis 11/19-B1 in mitigating allergic rhinitis symptoms in a mouse model.

Female BALB/c mice were fed a diet supplemented with heat-killed L. lactis 11/19-B1, while allergic rhinitis was induced via intraperitoneal and intranasal administration of ovalbumin (OVA). The positive control group received a standard diet without L. lactis 11/19-B1. Sneezing frequency was recorded, and tissue samples were collected for analysis. Serum OVA-immunoglobulin E (IgE) levels were also measured, nasal mucosa histopathology assessed, and the interleukin 4 (IL-4), interferon gamma (IFN-γ), T helper (Th) 1/Th2 balance in cluster of differentiation (CD) 4+ T cells analyzed by flow cytometry (FCM).

Mice receiving L. lactis 11/19-B1 showed significantly reduced sneezing frequency and decreased eosinophil infiltration in the nasal mucosa. No significant changes in serum OVA-IgE levels were observed. Flow cytometry analysis showed a significant increase in the Th1/Th2 ratio in Peyer's patches in the L. lactis 11/19-B1 group compared with the positive control group.

These findings suggest that L. lactis 11/19-B1 alleviates allergic rhinitis symptoms by modulating the Th1/Th2 balance and reducing eosinophil infiltration, independently of IgE suppression. These findings highlight its potential as a dietary supplement for allergic disease management .