Enhancement of Immune Functions by Limosilactobacillus reuteri KBL346: In Vitro and In Vivo Studies.

2023-12-21
International journal of molecular sciences 25(1)

PubMed: 38203313
DOI: 10.3390/ijms25010141

Study Design

Population: macrophages and cyclophosphamide (CPA)-induced immunosuppressed mice
Methods: We evaluated the immunostimulatory activity and hematopoietic function of KBL346 in macrophages and cyclophosphamide (CPA)-induced immunosuppressed mice. KBL346 increased the phagocytic activity against Candida albicans MYA-4788 in macrophages, and in CPA-induced immunosuppressed mice, KBL346 at a dosage of 10^10 CFU/kg was administered and compared with a Korean red ginseng positive control group. Safety was assessed by evaluating antibiotic resistance, hemolytic activity, cytotoxicity, and metabolic characteristics.

Rigorous Journal

Lactobacilli have been widely used as probiotics because of their benefits for intestinal health and physiological functions. Among a variety of Lactobacillus genera, Limosilactobacillus reuteri has been studied for its ability to exert anti-inflammatory functions and its role in controlling metabolic disorders, as well as the production of the antimicrobial compound reuterin. However, the effects and mechanisms of L. reuteri on enhancing immune responses in the immunosuppressed states have been relatively understudied. In this study, we isolated an immunomodulatory strain, namely, L. reuteri KBL346 (KBL346), from a fecal sample of a 3-month-old infant in Korea. We evaluated the immunostimulatory activity and hematopoietic function of KBL346 in macrophages and cyclophosphamide (CPA)-induced immunosuppressed mice. KBL346 increased the phagocytic activity against Candida albicans MYA-4788 in macrophages, and as biomarkers for this, increased secretions of nitric oxide (NO) and prostaglandin E₂ (PGE₂) were confirmed. Also, the secretions of innate cytokines (TNF-α, IL-1β, and IL-6) were increased. In CPA-induced immunosuppressed mice, KBL346 at a dosage of 10¹⁰ CFU/kg protected against spleen injury and suppressed levels of immune-associated parameters, including NK cell activity, T and B lymphocyte proliferation, CD4⁺ and CD8⁺ T cell abundance, cytokines, and immunoglobulins in vivo. The effects were comparable or superior to those in the Korean red ginseng positive control group. Furthermore, the safety assessment of KBL346 as a probiotic was conducted by evaluating its antibiotic resistance, hemolytic activity, cytotoxicity, and metabolic characteristics. This study demonstrated the efficacy and safety of KBL346, which could potentially be used as a supplement to enhance the immune system.

Research Insights

Supplement	Dose	Health Outcome	Effect Type	Effect Size	Source
Lactobacillus rhamnosus	—	Improved Immune Function	Beneficial	Moderate	View source KBL346 increased the phagocytic activity against Candida albicans MYA-4788 in macrophages... In CPA-induced immunosuppressed mice, KBL346... protected against spleen injury and suppressed levels of immune-associated parameters, including NK cell activity, T and B lymphocyte proliferation, CD4+ and CD8+ T cell abundance, cytokines, and immunoglobulins in vivo.
Lactobacillus rhamnosus	—	Improved Innate Immune Response	Beneficial	Moderate	View source KBL346 increased the phagocytic activity against Candida albicans MYA-4788 in macrophages... Also, the secretions of innate cytokines (TNF-α, IL-1β, and IL-6) were increased.
Lactobacillus rhamnosus	—	Reduced Immunosuppression-Related Spleen Injury	Beneficial	Moderate	View source In CPA-induced immunosuppressed mice, KBL346 at a dosage of 10^10 CFU/kg protected against spleen injury and suppressed levels of immune-associated parameters