12-PAHSA alleviated intestinal inflammation and barrier damage by promoting M2 macrophage polarization

Fatty acid esters of hydroxy fatty acids (FAHFAs) are endogenous functional lipids with limited research on macrophages-involved intestinal damage. In this study, in vitro screening of effective FAHFAs among ten isomers was performed on LPS-challenged RAW264.7 macrophages and IPEC-J2 epithelial cells, followed by in vivo verification on DSS-induced colitis mice. The results showed that ten isomers failed to directly improve epithelial barriers, while 12-PAHSA, 12-C17HSA, and 12-OAHSA effectively promoted M2 macrophage polarization in vitro , and their supernatant upregulated zonula occludens-1 ( ZO-1 ) of IPEC-J2 cells to enhance barriers. Furthermore, only 12-PAHSA effectively alleviated DSS-induced colitis by upregulating M2 macrophage biomarker of Arginase-1 (Arg1), anti-inflammatory IL-10, and barrier integrity-related ZO-1 and mucin-2 (MUC2). Notably, 12-PAHSA regulated macrophage polarization via GPR120 receptor. Our findings demonstrated that 12-PAHSA alleviated intestinal inflammation and barrier damage by promoting M2 macrophage polarization, highlighting its great potential as a nutritional intervention for improving intestinal health. • Ten FAHFAs failed to directly improve epithelial barrier in vitro . • 12-PAHSA, 12-C17HSA, and 12-OAHSA promoted M2 macrophage polarization in vitro . • 12-PAHSA-drived M2 macrophages improved epithelial barriers via GPR120 receptor. • Only 12-PAHSA alleviated DSS-induced gut inflammation and barrier damage in mice.