Study on the digestive characteristics of short-and medium-chain fatty acid structural lipid and its rapid intervention on gut microbes: In vivo and in vitro studies

Structuring is a feasible scheme to improve lipids' value. Here, SBL and SLBL (C4-C12 structural lipids) were obtained through enzymatic ester-ester transesterification or acidolysis interesterification using glyceryl tributyrate/glyceryl tridodecanoate and lauric acid/glyceryl tributyrate as raw materials, respectively. The digestive characteristics of SBL and SLBL were investigated in vitro and in vivo, meanwhile, their effects on gut microbes were studied. Compared with their corresponding triglyceride physical mixture, SBL possessed an ideal butyric acid sustained-release effect in simulated stomach digestion. Moreover, the sustained-release effect of SLBL on glycerol monolaurate (GML) was revealed both in vivo and in vitro, while this effect of the SBL was obviously occurred in small intestine. SBL significantly increased the abundance of Bifidobacterium and SLBL promoted the growth of Clostridiales within 24 h. Overall, both SBL and SLBL showed ideal sustained-release effects on GML rather than butyric acid, which may lead to positive changes in gut microbes.