Abstract
The gut microbiome is known to influence health and well-being beyond the gastrointestinal system, including metabolism, mood, and cognitive function. Research on the influence of the gut microbiome on cancer and cancer treatment has expanded in recent decades. This review discusses the effects of the gut microbiome on the pathogenesis of certain cancers, as well as the current guidelines and recommendations for health-care professionals for modifying the gut microbiome in cancer patients currently receiving chemotherapy or immunotherapy. The focus of this review is on five major areas of gut microbiome research (colorectal cancer, melanoma, renal cell carcinoma and non-small cell lung cancer, lymphoma, and acute leukemia) in which therapies, and particularly checkpoint inhibitors, have considerably improved survival outcomes. The relationship between microbial species and therapies to cure malignancies is largely unclear. This review will delineate the relationships being studied and conclusions to draw from the research in these areas thus far.