Longitudinal Analysis of the Immunostimulatory Properties and Safety Profile of Lacticaseibacillus rhamnosus LRa05 as a Dietary Supplement.

Supplementation with appropriate doses of Lacticaseibacillus rhamnosus has been reported to potentially attenuate immune changes. While some progress has been made in studying the immune function of L. rhamnosus LRa05, a lack of systematic summaries has led to the neglect of its application in enhancing immune function. This study aimed to investigate the effects of L. rhamnosus LRa05 on the immune function of mice and to evaluate its safety profile as a dietary supplement. Mice were divided into three dosage groups (0.205, 0.410, and 1.230 g/kg body weight [BW]) and a negative control group (PBS), with each group orally gavaged for 30 consecutive days. The study assessed body weight, organ-to-body weight ratio, cellular immune function, humoral immune function, monocyte-macrophage phagocytic function and NK cell activity. Additionally, a subsequent 90-day subchronic oral toxicity study was conducted on rats to evaluate the safety of LRa05 consumption. Significant differences were observed in the number of antibody-producing cells, carbon clearance function, and NK cell activity across all dosage groups compared to the negative control group, indicating that L. rhamnosus LRa05 has a superior ability to enhance immunity. During the 90-day subchronic oral toxicity experiment, no obvious damage was observed, demonstrating its good safety profile for consumption. This study underscores the immunopotentiating effects of L. rhamnosus LRa05 and its safety as a dietary supplement, recommending it as a promising candidate for integration into the food and health food industries.