Metabolic phenotypes are often altered during the process of tumor onset and development. This metabolic reprogramming mode not only comprises traditional nutrient sources (glucose, lipids, glutamine), but also lactate, acetate, ketone bodies and exogenous proteins can also be re⁃ingested and utilized by cancer cells. A healthy gut microbiota maintains homeostasis and normal intestinal function, and has important physiological significance in regulating host energy metabolism, promoting food digestion, and modulating immunity. However, the metabolites of the gut microbiota are capable of reshaping the nutritional microenvironment of tumors, forcing cancer cells to support their own proliferation and metastasis by changing their metabolic manners. In this paper, we systematically reviewed the nutrient sources involved in tumor metabolic reprogramming and its regulation by gut microbiota. On the one hand, tumor metabolism is reprogrammed, and tumor cells continuously absorb various nutrients from the surrounding environment to provide energy for their own growth and proliferation. On the other hand, the gut microbiota modulates the process of tumor metabolic reprogramming through its metabolites. At the same time, tumor metabolites possess a feed⁃back effect on the gut microbiota and then the intestinal ecological balance. It is particularly crucial to understand the mechanism of tumor metabolic reprogramming and reveal the interaction between the gut microbiota and tumor metabolism. This will provide a good theoretical basis for the exploration of effective metabolic targeted prevention and treatment strategy and potential drugs for cancer in the future.