Our data displayed that the upregulation of proinflammatory cytokines (IL-1β, IL-6, and TNF-α) in the colon tissues and serum were reduced by pretreatment with Os-EVs whereas Os-EVs are capable of promoting the expression of IL-10 (a well-known anti-inflammatory cytokine) in DSS-induced mice, which further supported the protective effect of Os-EVs on IBD in mice. Here, IL1B is linked to inflammatory bowel disease.