In biological responses, fatty acids (FA) are absorbed and metabolized in the form of substrates for energy production. The molecular structures (number of double bonds and chain length) and composition of dietary FA impact digestion, absorption and metabolism, and the biological roles of FA. Recently, increasing evidence indicates that FA are essentially utilized as an energy source and are signaling molecules that exert physiological activity of gut microbiota and immune responses. In addition, FA could serve as natural ligands for orphan G protein-coupled receptors (GPCR), also called free fatty acid receptors (FFAR), which intertwine metabolic and immune systems via multiple mechanisms. The present review explores the recent findings on FA absorption and its impact on gut health, particularly addressing the mechanism by which dietary FA potentially influences intestinal microbiota and epithelial functions. Also, this work attempts to uncover research ideas for devising future strategies for manipulating the composition of dietary FA to regulate gut health and support a normal immune system for metabolic and immune disorders.

在生物反应中，脂肪酸 (FA) 以底物的形式被吸收和代谢以产生能量。膳食脂肪酸的分子结构（双键数量和链长）和组成会影响消化、吸收和代谢，以及脂肪酸的生物学作用。最近，越来越多的证据表明 FA 主要用作能量来源，并且是发挥肠道微生物群生理活性和免疫反应的信号分子。此外，FA 可以作为孤儿 G 蛋白偶联受体 (GPCR) 的天然配体，也称为游离脂肪酸受体 (FFAR)，通过多种机制将代谢和免疫系统交织在一起。本综述探讨了最近关于 FA 吸收的发现及其对肠道健康的影响，特别是解决膳食 FA 可能影响肠道微生物群和上皮功能的机制。此外，这项工作试图揭示研究思路，以制定未来的策略，以操纵膳食 FA 的组成来调节肠道健康并支持代谢和免疫疾病的正常免疫系统。