THE COMPLEX EFFECT OF BIFIDOBACTERIUM AND LACTOBACILLUS SPECIES AND METFORMIN ON MACROPHAGES POLARIZATION IN IN VIVO STUDIES
DOI:
https://doi.org/10.15407/oncology.2026.02.118Keywords:
Ehrlich carcinoma, B. animalis subsp. lactis BB-12, L. rhamnosus GG, metformin, macrophages, polarization state, antitumor efficacyAbstract
Aim: to study the complex effect of the metformin and B. animalis subsp. lactis BB-12 or L. rhamnosus GG application on the polarization of peritoneal macrophages. Object and Methods: the studies were conducted on female Balb/c mice. Ehrlich adenocarcinoma (EAC) was used as an experimental tumor. Tumor-bearing animals were administered metformin or metformin in combination with B. animalis subsp. lactis BB-12 or L. rhamnosus GG for 20 days. The parameters of macrophages’ (Mph) functional activity were determined by the levels of NO and reactive oxygen species (ROS) production, arginase (Arg) activity, phagocytic and cytotoxic activity, and the production of TNF-α and IL-10 cytokines. Results: Metformin administered as single treatment caused a binary effect on the polarization state of Mph: it positively influenced Mph cytotoxic activity, a high NO/Arg ratio, and ROS production (characteristics of M1 Mph), while simultaneously increasing phagocytic activity (a sign of M2 Mph) and having a weak effect on cytokine production. At the same time, when combined with bacterial preparations, metformin synergized with the influence of bacteria on Mph polarization. Due to the decreased NO/Arg ratio and cytotoxic activity concomitantly with the increased phagocytic activity, and the spectrum of produced cytokines metformin in combination with B. animalis subsp. lactis BB-12 supported Mph polarization toward one of the M2 subtypes. In contrast, the combined administration of metformin and L. rhamnosus GG promoted M1-type Mph polarization, as indicated by the prolonged preservation of Mph cytotoxic activity, their ability to produce high levels of NO, ROS, and TNF-α, while decreasing phagocytic activity and IL-10 production. Combined administration of metformin with bacterial preparations (but not metformin alone) contributed to tumor growth inhibition by 56.2% (B. animalis + metformin) and 62.0% (L. rhamnosus + metformin). Tumor volume inversely correlated with NO/Arg ratio or Mph cytotoxic activity (r equals to -0.785 and -0.742, respectively, p < 0.05 in both cases). Conclusion: combining metformin with bacterial preparations did not significantly alter the effect of the latter on macrophage (Mph) polarization, while demonstrating a pronounced antitumor effect. These findings highlight the potential of this combination for targeted immunocorrection, overcoming tumor-mediated immunosuppression, and enhancing the efficacy of cancer treatment.
References
Zeng J, He Z, Wang G, et al. Interaction between microbiota and immunity: molecular mechanisms, biological functions, diseases, and new therapeutic opportunities. MedComm 2025; 6 (7): e70265. https://doi.org/10.1002/mco2.70265
Böhm D, Russ E, Guchelaar HJ, et al. The role of the gut microbiota in chemotherapy response, efficacy and toxicity: a systematic review. Npj Precis Oncol 2025; 9 (1): 265. https://doi.org/10.1038/s41698-025-01034-0
Mafe AN, Büsselberg D. et al. Microbiome integrity enhances the efficacy and safety of anticancer drug. Biomedicines 2025; 13 (2): 422. https://doi.org/10.3390/biomedicines13020422
Cohen I, Ruff WE, Longbrake EE. et al. Influence of immunomodulatory drugs on the gut microbiota. Transl Res 2021; 233: 144–61. https://doi.org/10.1016/j.trsl.2021.01.009
Zheng D, Liwinski T, Elinav E. et al. Interaction between microbiota and immunity in health and disease. Cell Res 2020; 30 (6): 492–506. https://doi.org/10.1038/s41422-020-0332-7
Buczyńska A, Sidorkiewicz I, Krętowski AJ, et al. Examining the clinical relevance of metformin as an antioxidant intervention. Front Pharmacol 2024; 15: 1330797. https://doi.org/10.3389/fphar.2024.1330797
Jafarzadeh S, Nemati M, Zandvakili R, et al. Modulation of M1 and M2 macrophage polarization by metformin: Implications for inflammatory diseases and malignant tumors. Int Immunopharmacol 2025; 151: 114345. https://doi.org/10.1016/j.intimp.2025.114345
Jiang LL, Liu L. Effect of metformin on stem cells: Molecular mechanism and clinical prospect. World J Stem Cells 2020; 12 (12): 1455–73. https://doi.org/10.4252/wjsc.v12.i12.1455
Manica D, Sandri G, Da Silva GB, et al. Evaluation of the effects of metformin on antioxidant biomarkers and mineral levels in patients with type II diabetes mellitus: A cross-sectional study. J Diabetes Complications 2023; 37 (7): 108497. https://doi.org/10.1016/j.jdiacomp.2023.108497
Nassif RM, Chalhoub E, Chedid P, et al. Metformin inhibits ROS production by human M2 macrophages via the activation of AMPK. Biomedicines 2022; 10 (2): 319. https://doi.org/10.3390/biomedicines10020319
Qing L, Fu J, Wu P, et al. Metformin induces the M2 macrophage polarization to accelerate the wound healing via regulating AMPK/mTOR/NLRP3 inflammasome singling pathway. Am J Transl Res 2019; 11 (2): 655–68.
Wang Z, Wang M, Lin M, et al. The immunomodulatory effects of metformin in LPS-induced macrophages: an in vitro study. Inflamm Res 2024; 73 (2): 175–81. https://doi.org/10.1007/s00011-023-01827-8
Chiang CF, Chao TT, Su YF, et al. Metformin-treated cancer cells modulate macrophage polarization through AMPK-NF-κB signaling. Oncotarget 2017; 8 (13): 20706–18. https://doi.org/10.18632/oncotarget.14982
Saito A, Kitayama J, Horie H, et al. Metformin changes the immune microenvironment of colorectal cancer in patients with type 2 diabetes mellitus. Cancer Sci 2020; 111 (11): 4012–20. https://doi.org/10.1111/cas.14615
European Convention for the Protection of Vertebrate Animals used for Experimental and other Scientific Purposes ETS 123. Protection of Vertebrate Animals, 18.III.1986. 48. https://norecopa.no/media/2iydns5h/ets-123-original. pdf
Radulski DR, Stipp MC, Galindo CM, et al. Features and applications of Ehrlich tumor model in cancer studies: a literature review. Transl Breast Cancer Res 2023; 4: 22–22. https://doi.org/10.21037/tbcr-23-32
Gogol S, Virych P, Fedosova N, et al. Immunomodulating effect of probiotics B. animalis subsp. lactis BB-12 and L. rhamnosus GG during tumor growth. Oncology 2025; 27 (2): 129–38. https://doi.org/10.15407/oncology.2025.02.129
Chumak AV, Fedosova NI, Cheremshenko NL, et al. Macrophage polarization in dynamics of Lewis lung carcinoma growth and metastasis. Exp Oncol 2021; 43 (1): 1. https://doi.org/10.32471/exp-oncology.2312-8852.vol-43-no-1.15829
Symchych TV, Fedosova NI, Chumak AV, et al. Functions of tumor-associated macrophages and macrophages residing in remote anatomical niches in Ehrlich carcinoma bearing mice. Exp Oncol 2020; 42 (3): 3. https://doi.org/10.32471/exp-oncology.2312-8852.vol-42-no-3.14928
Marcucci F, Romeo E, Caserta CA, et al. Context-dependent pharmacological effects of metformin on the immune system. Trends Pharmacol Sci 2020; 41 (3): 162–71. https://doi.org/10.1016/j.tips.2020.01.003
Gao J, Liang Y, Wang L, et al. Shaping polarization of tumor-associated macrophages in cancer immunotherapy. Front Immunol 2022; 13: 888713. https://doi.org/10.3389/fimmu.2022.888713 .
Ohlsson SM, Linge CP, Gullstrand B, et al. Serum from patients with systemic vasculitis induces alternatively activated macrophage M2c polarization. Clin Immunol 2014; 152 (1–2): 10–9. https://doi.org/10.1016/j.clim.2014.02.016 .
Wang LX, Zhang SX, Wu HJ, et al. M2b macrophage polarization and its roles in diseases. J Leukoc Biol 2019; 106 (2): 345–58. https://doi.org/10.1002/JLB.3RU1018-378RR .
Fedosova N, Symchych T, Gogol S, et al. Influence of Bifidobacterium animalis subsp. lactis BB-12 and Lactobacillus rhamnosus GG on polarization of tumour associated macrophages. Exp Oncol 2026; 47 (4): 451–8. https://doi.org/10.15407/exp-oncology.2025.04.451.
