Introduction: The gut microbiota is a complex ecosystem that regulates key physiological processes,including immunity, metabolism, and inflammation. Increasing evidence links dysbiosis to the initiation, progression, and therapeutic responsiveness of cancer, positioning the microbiota as a key factor in oncogenesis and oncology care. This systematic review synthesizes recent advances in understanding the role of gut microbiota in cancer biology and evaluates current knowledge on microbiome-targeted interventions designed to optimize clinical outcomes.

Materials and Methods: A literature search was conducted in PubMed and Scopus databases, using PRISMA guidelines and focusing on articles published in English between December 2024 and July 2025. Of the 8,965 studies initially identified, 27 met the inclusion criteria and were analyzed in review.

Results: Recent evidence highlights microbiota’s role in cancer biology, with microbial metabolites and gut taxa shown to influence carcinogenesis, tumor progression, and therapy response. Distinct microbial profiles are emerging as predictive biomarkers for treatment efficacy, while microbiota-targeted interventions, including FMT, probiotics, prebiotics, and postbiotics, demonstrate potential in improving therapeutic outcomes and reducing treatment-related toxicity.

Conclusions: The year 2025 has brought advancements in understanding microbiota’s role in cancer biology. These findings highlight that gut microbiota is a modifiable determinant in precision oncology, supporting the integration of microbiome-based strategies into personalized cancer treatment.