The effect mechanism of polysaccharides inhibit tumor immune escape: A review

[Display omitted] •Various factors lead to tumor immune escape.•Polysaccharides can regulate the immune function of the body as a natural immune regulators.•Polysaccharides alter the gut microbiota, modulating the anti-tumor effect of anti-PD-1/PD-L1.•Polysaccharides induce ferroptosis in cancer cells through the xCT/GPX4 pathway.•Polysaccharides inhibit tumor immune escape. A disorder of the immune system is the fundamental cause of cancer. The body can defend against external threats only when the immune system is robust. Polysaccharides are natural immune regulators that can regulate the immune function of the body at multiple levels and targets. Recent studies have shown that polysaccharides can inhibit tumor growth by stimulating the immune system, thereby promoting immune cell proliferation, increasing cytokine secretion, and regulating the immune functions of the body as a whole. However, there are few reports on the potential mechanism by which polysaccharides inhibit tumor immune escape. Therefore, this article reviews the immune anti-tumor effect of polysaccharides, the mechanism by which they inhibit tumor immune escape, and their signaling pathways, in order to provide a theoretical basis for the development of anti-tumor drugs and malignant tumor treatment.