Fish oil and flax seed oil supplemented diets increase FFAR4 expression in the rat colon

Background and objective Omega-3 fatty acids, such as α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), are polyunsaturated fatty acids (PUFA) that have long been associated with anti-inflammatory activity and general benefit toward human health. Over the last decade, the identification of a family of cell-surface G protein-coupled receptors that bind and are activated by free-fatty acids, including omega-3 fatty acids, suggest that many effects of PUFA are receptor-mediated. One such receptor, free-fatty acid receptor-4 (FFAR4), previously described as GPR120, has been shown to modulate anti-inflammatory and insulin-sensitizing effects in response to PUFA such as ALA and DHA. Additionally, FFAR4 stimulates secretion of the insulin secretagogue glucagon-like peptide-1 (GLP-1) from the GI tract and acts as a dietary sensor to regulate energy availability. The aim of the current study was to assess the effects of dietary omega-3 fatty acid supplementation on FFAR4 expression in the rat colon.