Fermente gidalardan izole edilen yeni probiyotik suşlarin postbiyotiklerinin anti-kanser etkisi

Colorectal cancer ranks among the most prevalent and lethal malignancies globally, with increasing interest in the role of gut microbiota and their metabolites in both the onset and prevention of this disease. This dissertation examines the potential therapeutic effects of probiotics and their postbiotic metabolites on colorectal cancer, utilizing two human colon cancer cell lines—HCT116 and HT29—as experimental models. The research was conducted in two primary phases. The initial phase involved the isolation and comprehensive characterization of various probiotic strains, including an assessment of their morphological and biochemical properties, enzymatic activities (such as protease, lipase, and esterase production), and antioxidant capacity. These functional characteristics were employed to evaluate the probiotic potential of the strains, with a particular emphasis on Lactobacillus and Bacillus species, known for their beneficial effects on gastrointestinal health. In the subsequent phase, cell culture-based experiments were conducted to evaluate the effects of postbiotics on the HCT116 and HT29 colon cancer cells. The experimental setup included multiple cellular assays to investigate various aspects of cancer cell behavior. The MTS assay was utilized to assess cell viability and metabolic activity, while flow cytometry was employed to analyze changes in the cell cycle and quantify apoptosis. Additionally, RT-PCR analysis was performed to measure the expression levels of key genes involved in apoptosis (e.g., Caspase 3, 7, 8, BAX, P53), and cell cycle regulation (CDK1, CDK2, CDK4, CDK6). These molecular analyses provided insights into how postbiotics influence signaling pathways related to cancer cell growth and death. This research highlights the ability of selected probiotic strains to produce postbiotic compounds that may inhibit cancer cell proliferation, induce programmed cell death, and disrupt the cell cycle. By demonstrating that postbiotics can modulate critical cellular and molecular processes in colorectal cancer cells, this work paves the way for new strategies in cancer prevention and therapy. Further in vivo studies and clinical trials are necessary to validate these effects and explore their safety, efficacy, and mechanism of action in a physiological context.