Longitudinal Analysis of the Immunostimulatory Properties and Safety Profile of <i>Lacticaseibacillus rhamnosus</i> LRa05 as a Dietary Supplement

Supplementation with appropriate doses of <i>Lacticaseibacillus rhamnosus</i> has been reported to potentially attenuate immune changes. While some progress has been made in studying the immune function of <i>L. rhamnosus</i> 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 <i>L. rhamnosus</i> 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 <i>LRa05</i> 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 <i>L. rhamnosus</i> 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 <i>L. rhamnosus</i> LRa05 and its safety as a dietary supplement, recommending it as a promising candidate for integration into the food and health food industries.