Abstract: The interaction between gut microbiota-derived metabolites and the body plays an important role in the occurrence and development of cancer. Short-chain fatty acids (SCFAs), such as acetate, propionate, and butyrate, are important products produced from gut microbial fermentation of dietary fibers. Studies have shown that SCFAs exert anti-cancer effects by promoting apoptosis and cell cycle arrest in cancer cells, thereby preventing their metastasis and invasion. These effects are achieved by acting on G protein-coupled receptors (GPCR), up-regulating histone acetylation and croton acylation. In addition, this review illustrates that SCFAs play an important role in enhancing the function of immune cells.