The effect of Lacticaseibacillus rhamnosus LRa05 probiotic tablets on the immune function of mice and its safety

Lactobacillus rhamnosus LRa05 has been studied and used in food production due to its widely recognized probiotic properties. In order to investigate the safety of Lactobacillus rhamnosus LRa05 consumption and its effect on immune function in mice. In this study, three genotoxicity tests, including bacterial reverse mutation test, mammalian erythrocyte micronucleus test and mouse sperm cell chromosome aberration test, were performed on LRa05 probiotic tablets. The results of the genotoxicity tests were all negative, indicating that Lactobacillus rhamnosus LRa05 tablets had no mutagenic effect at the dose levels evaluated in this study. Meanwhile, in order to investigate whether LRa05 probiotic tablets could improve the immune function of mice, three dose groups were used and continuously gavaged for 30 d. The effects of Lactobacillus rhamnosus LRa05 probiotic tablets on the immune function of mice were evaluated by body weight, organ/body weight ratio, cellular immune function, humoral immune function, phagocytosis of monocyte-macrophages and NK cell activity. The results showed that compared with the negative control group, NK cell activity was significantly enhanced in all dose groups ( P < 0.05), the number of antibody-producing cells was significantly increased in the high-dose group ( P < 0.05), and phagocytosis of chicken erythrocytes by macrophages was significantly enhanced in the medium- and high-dose groups (P < 0.05).In conclusion, Lactobacillus rhamnosus LRa05 probiotic tablets have potential immunomodulatory activity ability and high safety for consumption, which can lay a good foundation for the application of Lactobacillus rhamnosus LRa05 probiotic tablets. The effect of Lacticaseibacillus rhamnosus LRa05 probiotic tablets on the immune function of mice and its safety. • Lactobacillus rhamnosus is a safe and effective probiotic. • Lactobacillus rhamnosus LRa05 have no mutagenic effect at the specified dose level. • Lymphocyte transformation and NK cell activity were enhanced in all dose groups compared to negative controls. • Lactobacillus rhamnosus LRa05 have potential immunomodulatory activity and high edible safety.