Heat-killed Lactobacillus paracasei K71 isolated from Sakekasu (sake lees) enhances Th1 response, NK cell cytotoxicity and fecal IgA content in normal BALB/c mice

• Published in: FOOD SCIENCE AND TECHNOLOGY RESEARCH Vol. 28; no. 4; pp. 335 - 341
• Main Authors: Hara, Takashi, Igarashi, Akira, Teradaira, Takuya, Joh, Toshio
• Format: Journal Article
• Language: English
• Published: Tsukuba Japanese Society for Food Science and Technology 01.01.2022; The Japanese Society for Food Science and Technology; Japan Science and Technology Agency
• Subjects: Cell culture; Cytotoxicity; Dietary supplements; fecal IgA; Heat; IFN-γ; Immune response; Immunoglobulin A; Immunoglobulin G; Immunostimulation; Innate immunity; Interleukin 12; Interleukin 4; Lactobacilli; Lactobacillus paracasei; Lactobacillus paracasei K71; Lymphocytes T; Natural killer cells; NK cells; Spleen; Th1 type immune responses; Toxicity; Tumorigenesis; γ-Interferon
• ISSN: 1344-6606; 1881-3984
• DOI: 10.3136/fstr.FSTR-D-21-00290

Lactobacillus paracasei K71 (K71) isolated from Japanese sake lees (Sakekasu) was previously shown to enhance IL-12 production in mouse spleen cell culture. In this study, we examined whether heat-killed K71 exerts immunostimulatory effects in normal BALB/c mice. Six-week dietary supplementation with 0.2% heat-killed K71 resulted in significantly higher levels of serum IgG2a and fecal IgA than control mice. Upon administration, heat-killed K71 increased IFN-γ production in Peyer's patch cells while simultaneously suppressing IL-4 production in spleen cells. Spleen cells from mice fed heat-killed K71 exhibited a significant increase in cytotoxicity against YAC-1 cells. Furthermore, splenic CD49b+NKp46+ NK cells from mice fed heat-killed K71 showed significantly enhanced IFN-γ production. These results suggest that oral intake of K71 may augment Th1 type immune function and innate immunity, thereby potentially preventing infections and/or tumorigenesis.