The decreased interface tension increased the transmembrane transport of soy hull polysaccharide-derived SCFAs in the Caco-2 cells

Polysaccharides impact intestinal fermentation and regulate interfacial properties which affect absorption and transportation. Short-chain fatty acids (SCFAs), the main metabolites of soy hull polysaccharide lysate, are readily absorbed by the body and perform various physiological functions. We analysed the interfacial properties and transport of soy hull polysaccharide-derived SCFAs in the Caco-2 cell model to clarify the transmembrane transport mechanism. The results showed that the interfacial properties of the co-culture system were influenced by both transit time and concentration of SCFAs, the uptake and transit rates of SCFAs at 1–3 h increased significantly with time (P < 0.05). With increasing transit time and concentration, the transit rates of SCFAs on the apical side (AP) → basolateral side (BL) and BL → AP sides increased and then stabilised, the transit rate of the AP → BL side was higher than that of the BL → AP side. Proteomic analysis showed that soy hull polysaccharide-derived SCFAs resulted in the differential expression of 285 upregulated and 501 downregulated after translocation across Caco-2 cells. The differentially expressed proteins were mainly enriched in ribosomes, oxidative phosphorylation, nuclear transport, and SNARE vesicular transport. This study lays the theoretical foundation for understanding the structure-activity relationship of soy hull polysaccharides in the intestine.