Figure 3.

Exosomes mediate communication between intestinal microbes and host cells and together maintain the balance of the intestinal microenvironment. Exosomes from healthy intestinal microbes promote food metabolism, protect intestinal barrier integrity, and promote maturation of intestinal immune cells, whereas exosomes from intestinal host cells regulate the abundance and diversity of intestinal microbes. Conversely, exosomes from dysregulated intestinal microbiota adversely affect food metabolism, disrupt the integrity of the intestinal barrier, and lead to immune dysfunction, while exosomes from intestinal host cells cause dysregulation of the intestinal microbiota. Both intestinal microbial-derived exosomes that enter the circulation through the disrupted intestinal barrier and microbial-derived exosomes in feces can be used for liquid biopsies.