Reduction of intestinal fat digestion and absorption by β-glucan secreted by Rhizobium pusense via interference in triglyceride hydrolysis

In this study, the ability of β-glucan extracted from Rhizobium pusense to reduce digestion and absorption of ingested fat was systematically investigated via in vitro and in vivo experiments. Specifically, in in vitro gastrointestinal simulations, when β-glucan was added to a high-fat food model, the concentration of free fatty acids (FFAs) were remarkably decreased. An in vitro intestinal epithelial cell model demonstrated that addition of β-glucan can significantly reduce the translocation of triglycerides (TGs) and FFAs. In in vivo experiments, a high-fat food model with the addition of β-glucan showed a significant reduction in postprandial serum TG elevation. Confocal laser scanning microscopy analysis showed that when β-glucan was added to a cream sample, both coalescence and disappearance of lipid droplets were reduced, and the distribution of oil droplets was very consistent with the distribution of β-glucan positions. This suggests the main mechanism for this effect: the coagulation of lipid droplets by β-glucan leads to a reduction in the available surface area for lipase binding. All these findings suggest that β-glucan could potentially be used as a food additive or supplement to reduce the absorption of ingested fat and thus aid in weight loss and the treatment of diseases caused by TGs.