Neoplasms immunotherapy has made a major breakthrough in the clinical practice of refractory tumor. However, there are still individual differences in treatment results and drug resistance in clinical application. Gastrointestinal microbiome is gradually recognized as an immunoregulatory factor in recent years, and more and more studies have focused on its influences on the efficacy of tumor immunotherapy. Targeting gastrointestinal microbiota to improve the response of tumor patients to immunotherapy has potential clinical application value.