INFLUENCE OF BIFIDOBACTERIUM ANIMALIS SUBSP. LACTIS BB-12 AND LACTOBACILLUS RHAMNOSUS GG ON POLARIZATION OF...

Area of Science:

• Immunology
• Microbiology
• Cancer Research

Background:

• The host immune system is significantly influenced by the gut microbiota.
• Microbiome effects are species, strain, and context-dependent.
• Tumor-associated macrophages (TAMs) play a critical role in cancer progression.

Purpose of the Study:

• To investigate the impact of Bifidobacterium animalis subsp. lactis BB-12 (BB-12) and Lactobacillus rhamnosus GG (LGG) on TAM polarization.
• To evaluate the functional consequences of probiotic-induced TAM polarization in a mouse model of Ehrlich carcinoma.

Main Methods:

• Female Balb/c mice with Ehrlich carcinoma were gavaged with BB-12, LGG, or saline.
• TAMs were isolated from tumor tissue on days 14, 21, and 28 post-tumor inoculation.
• Functional analyses included nitric oxide (NO) production, arginase activity, reactive oxygen species (ROS) production, and cytotoxic activity.

Main Results:

• LGG supplementation induced M1 TAM polarization, characterized by high NO and ROS production and cytotoxic activity.
• BB-12 supplementation resulted in M2 (potentially M2b) TAM polarization, with high arginase activity but preserved in vitro cytotoxic activity.
• Different probiotic strains elicited distinct TAM polarization states.

Conclusions:

• Probiotic consumption, specifically BB-12 and LGG, modulates TAM polarization in experimental tumors.
• Both BB-12 and LGG demonstrate potential in influencing the tumor microenvironment through TAM modulation.