Fig. 3

Model summarizing the immunomodulatory mechanisms of omega-3 polyunsaturated fatty acids in the intestinal epithelium. In arachidonic acid (ARA)-enriched cell membranes, during an infection or injury, pathogen-associated molecular patterns (PAMPs) or damage-associated molecular patterns (DAMPs) binds with the host-specific pattern-recognizing receptors (PRRs) and activate the nuclear factor-κB (NF-κB) signaling to release pro-inflammatory cytokines, chemokines and reactive oxygen species (ROS). Subsequently, these mediators recruit the inflammatory cells from lamina propria and exert a strong pro-inflammatory response. Pro-inflammation also damages the integrity of the epithelial barrier by disrupting the tight junction proteins. Loss of epithelial integrity aggravates inflammation by facilitating the translocation of luminal pathogens and endotoxins into the circulatory system (Black lines). Dietary supplementation of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) ameliorates the pro-inflammatory response by replacing ARA in specific cell membrane G-protein-coupled receptors (GPCR) and instead stimulates the production of anti-inflammatory cytokines and antioxidants (Red lines). For references, see text. Figure created using BioRender.com