Fig. 2

Schematic representation of the role of PEVs in the maintenance of host intestinal homeostasis. Figure 2 firstly demonstrates the functions of various PEVs in maintaining intestinal homeostasis by down-regulating inflammatory signaling pathways to alleviate inflammation; regulating the levels of intestinal epithelial cell tight junction proteins to maintain the integrity of the intestinal barrier and improving the intestinal microbiota. In addition, PEVs enhanced the tumor-killing effect of CD8⁺ T cells by regulating intestinal microbial metabolites; induced tumor cells apoptosis by regulating the expression of mitochondrial and endoplasmic reticulum stress and apoptosis proteins; and induced the polarization of macrophages toward M1-type killing phenotypes, which emphasized the anticolonic tumor effect of PEVs