Lactobacillus brevis BGZLS10-17 and Lb. plantarum BGPKM22 Exhibit Anti-Inflammatory Effect by Attenuation of NF-κB and MAPK Signaling in Human Bronchial Epithelial Cells

Bronchial epithelial cells are exposed to environmental influences, microbiota, and pathogens and also serve as a powerful effector that initiate and propagate inflammation by the release of proinflammatory mediators. Recent studies suggested that lung microbiota differ between inflammatory lung diseases and healthy lungs implicating their contribution in the modulation of lung immunity. Lactic acid bacteria (LAB) are natural inhabitants of healthy human lungs and also possess immunomodulatory effects, but so far, there are no studies investigating their anti-inflammatory potential in respiratory cells. In this study, we investigated immunomodulatory features of 21 natural LAB strains in lipopolysaccharide (LPS)-stimulated human bronchial epithelial cells (BEAS-2B). Our results show that several LAB strains reduced the expression of pro-inflammatory cytokine and chemokine genes. We also demonstrated that two LAB strains, Lactobacillus brevis BGZLS10-17 and Lb. plantarum BGPKM22, effectively attenuated LPS-induced nuclear factor-kappa B (NF-kappa B) nuclear translocation. Moreover, BGZLS10-17 and BGPKM22 reduced the activation of p38, extracellular signal-related kinase (ERK), and c-Jun amino-terminal kinase (JNK) signaling cascade resulting in a reduction of pro-inflammatory mediator expressions in BEAS-2B cells. Collectively, the LAB strains BGZLS10-17 and BGPKM22 exhibited anti-inflammatory effects in BEAS-2B cells and could be employed to balance immune response in lungs and replenish diminished lung microbiota in chronic lung diseases.

Automated summary

Bronchial epithelial cells are exposed to environmental influences, microbiota, and pathogens and initiate inflammation. Recent studies have found that lung microbiota differ between inflammatory lung diseases and healthy lungs, indicating their contribution to lung immunity. This study investigated the anti-inflammatory effects of 21 natural LAB strains in LPS-stimulated human bronchial epithelial cells (BEAS-2B). The results showed that several LAB strains reduced the expression of pro-inflammatory cytokine and chemokine genes. Two LAB strains, Lactobacillus brevis BGZLS10-17 and Lb. plantarum BGPKM22, effectively attenuated LPS-induced NF-kappa B nuclear translocation and the activation of p38, ERK, and JNK signaling cascade, resulting in a reduction of pro-inflammatory mediator expressions in BEAS-2B cells. These LAB strains could be used to balance immune response in lungs and replenish diminished lung microbiota in chronic lung diseases.