Medium-chain fatty acids (MCFAs) are the main form of Medium Chain Triglycerides (MCTs) utilized by monogastric animals. MCFAs can be directly absorbed and supply rapid energy to promote the renewal and repair of intestinal epithelial cells, maintain the integrity of intestinal mucosal barrier function, and reduce inflammation and stress. In our review, we pay more attention to the role of MCFAs on intestinal microbiota and mucosa immunity to explore MCFA's positive effect. It was found that MCFAs and their esterified forms can decrease pathogens while increasing probiotics. In addition, being recognized via specific receptors, MCFAs are capable of alleviating inflammation to a certain extent by regulating inflammation and immune-related pathways. MCFAs may also have a certain value to relieve intestinal allergy and inflammatory bowel disease (IBD). Unknown mechanism of various MCFA characteristics still causes dilemmas in the application, thus MCFAs are used generally in limited dosages and combined with short-chain organic acids (SOAs) to attain ideal results. We hope that further studies will provide guidance for the practical use of MCFAs in animal feed.

中链脂肪酸（MCFA）是单胃动物利用的中链甘油三酸酯（MCT）的主要形式。MCFA可以被直接吸收并提供快速的能量，以促进肠上皮细胞的更新和修复，维持肠粘膜屏障功能的完整性，并减轻炎症和压力。在我们的综述中，我们更加关注MCFA在肠道菌群和粘膜免疫中的作用，以探索MCFA的积极作用。发现MCFA及其酯化形式可以减少病原体，同时增加益生菌。此外，MCFA通过特殊的受体识别，能够通过调节炎症和免疫相关途径在一定程度上减轻炎症。MCFA也可能具有一定的缓解肠道过敏和炎症性肠病（IBD）的价值。各种MCFA特性的未知机制仍在应用中造成难题，因此MCFA通常以有限的剂量使用，并与短链有机酸（SOA）结合使用以获得理想的结果。我们希望进一步的研究将为动物饲料中MCFA的实际使用提供指导。