Screening and Probiotic Properties of Lactic Acid Bacteria with Potential Immunostimulatory Activity Isolated from Kimchi

The modulation of the immune system is a major mechanism through which probiotics exert beneficial effects on health. Probiotics, including lactic acid bacteria (LAB), have been reported to enhance innate immunity. The purpose of this study was to screen for LAB strains with excellent immunostimulatory activity isolated from kimchi. We selected five promising strains (Limosilactobacillus fermentum MG5489, Lactococcus lactis MG5542, Lacticaseibacillus paracasei MG5559, Latilactobacillus sakei MG5468, and Latilactobacillus curvatus MG5609) that exhibited immune-stimulating effects by inducing the production of nitric oxide (NO) and pro-inflammatory cytokines such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and IL-1 beta in RAW264.7 cells. The selected strains significantly increased phagocytic activity of RAW264.7 cells and nuclear factor-kappa B (NF-kappa B) activation. Furthermore, the safety of the selected strains was determined using hemolysis and antibiotic susceptibility tests. The stabilities and adhesion abilities of these strains in the gastrointestinal tract (GIT) were also determined. Taken together, these findings suggest that the strains selected in this study have the potential to be novel probiotics to enhance immunity.

Automated summary

This study screened and identified five strains of immunologically active lactic acid bacteria, including Limosilactobacillus fermentum MG5489, Lactococcus lactis MG5542, Lacticaseibacillus paracasei MG5559, Latilactobacillus sakei MG5468, and Latilactobacillus curvatus MG5609. These strains enhanced immunity by inducing the production of nitric oxide, tumor necrosis factor-alpha, interleukin-6, and interleukin-1 beta in RAW264.7 cells, as well as increasing phagocytic activity and nuclear factor-kappa B activation. Furthermore, the strains exhibited stability and adhesion in the gastrointestinal tract. Overall, these selected strains have the potential to be novel probiotics for enhancing immunity.