Soy hull polysaccharide encapsulated tributyrin delivery system exhibits gut microbiota responsive release and improved high butyric acid state in vitro

Butyric acid is the main nutrient of intestinal epithelium, but it has an unpleasant odor. In order to increase the content of butyric acid in the intestine, soy hull polysaccharide (SHP) nanomicelle carrier was designed to deliver the precursor of butyric acid, tributyrin (TB). The SHP nanomicelles were characterized by laser particle size analyzer, XRD and AFM. And the effects of nanomicelles on the interfacial properties of the digestive system were investigated by simulating the gastrointestinal tract in vitro . The results show that SHP–TB nanomicelles are spherical. The peak value of C=O tensile vibration at 1650 cm −1 increased. The inclusion rate reached 30.44%, and the loading rate was 80.51%. The cumulative TB release rate was <20% after 2 h of release in the stomach and was <25% after 4 h of release in the small intestine, and the cumulative release rate in the colon reached >95%. With prolongation of fermentation, the OD 600 of the fermentation solution significantly increased, the pH and total sugar content significantly decreased, and total sugar utilisation rate >66.04%. The butyric acid content in the fermentation solution significantly increased and the proportion was above 0.4 on average, the average contents of total SCFAs increased from 2.04 mmol/L to 45.79 mmol/L, the interfacial tension decreased and tended to be stable at the late stage of interfacial adsorption. At a 1:0.5 mass ratio, the SHP–TB nanomicelles exhibited the best cell survival rate and colysis process, with no toxicity. Therefore, SHP nanomicelles can target TB delivery as an ideal carrier in the colon, and the intestinal environment is conducive to the degradation of TB into acid, promoting absorption in the body.