The Human Microbiome: An Overview of Microbial Mechanisms, Diagnostics, and Therapeutic Modulation in Cancer

The human microbiome consists of trillions of microbes (microorganisms) residing in various locations in the body, but primarily in the gut. It plays a vital role in health maintenance and influences several diseases, including cancer. Emerging evidence suggests that microbial dysbiosis, characterized by an imbalance in microbial numbers and diversity, may contribute to cancer development through several mechanisms, including the release of genotoxins, altered metabolism, immune system modulation, and chronic inflammation. This narrative review compiles existing insights into the interactions between the microbiome and cancer, with a particular emphasis on microbial mechanisms during carcinogenesis and the contributions of the microbiome to the diagnosis and treatment of cancer. We examine the potential use of prebiotics, probiotics, fecal microbiota transplants, and microbial therapies that may influence cancer and its response to treatment. Gaining a deeper understanding of the intricate relationship between microbial communities and cancer could lead to groundbreaking methods for cancer prevention and therapy.