Effects of <i>Lactobacillus acidophilus</i> and <i>Lactobacillus plantarum</i> on Survival and Proliferation of Breast Cancer Cell Line MCF-7

Abstract Conventional treatments for breast cancer use cytotoxic drugs, which cause severe side effects. Researchers are seeking new treatments with fewer side effects and greater efficacy. Probiotics, such as Lactobacillus species, have demonstrated positive effects on various diseases, including cancer. The probiotics Lactobacillus acidophilus and Lactobacillus plantarum were examined using MCF-7 and MCF-10A human breast cancer and normal human breast cell lines, respectively. The cell lines were treated with the supernatant and probiotic pellets, and cell proliferation, viability, apoptosis, and BCL2 gene expression were evaluated. The culture supernatant of L. plantarum significantly inhibited the growth of MCF-7 cell line compared to other groups, including the group treated with both probiotics. The supernatant of L. plantarum increased apoptosis and significantly reduced BCL2 gene expression in MCF-7 cells. No effects were observed in MCF-10A cells. The findings indicated that the supernatant of L. plantarum had a stronger cytotoxic effect on MCF-7 cells. In contrast, the combination of L. plantarum and L. acidophilus showed no synergistic effects. These results suggest that metabolites in the supernatant of L. plantarum contribute to the cytotoxic effects of this probiotic. This probiotic is a promising candidate for breast cancer treatment, and further research is needed to understand its preventive and therapeutic mechanisms.