Circulating triglycerides and bile acids are reduced by a soluble wheat arabinoxylan via modulation of bile concentration and lipid digestion rates in a pig model

Abstract

Scope: Soluble dietary fibres have shown to have lipid reducing properties. However, their mechanisms of action are still unclear. The present study investigated how a soluble wheat arabinoxylan‐rich fraction (AXRF) fed to pigs used as a human model reduced blood triglycerides. Methods and results: After 4 weeks on the experimental diets, blood from the jugular (JV) and hepatic portal (HPV) veins, bile from the gall bladder, and digesta samples from four sites of the small intestine (SI) and cecum were collected. The results showed that the AXRF significantly decreased the concentrations of total bile acid (BA) in the HPV (p < 0.01), JV (p < 0.01), bile (p < 0.05) and SI (p < 0.05), but with no effect on ileal BAs excretion flux. Furthermore, blood triglyceride (TAG) levels were also lower with AXRF (p < 0.01) but with no significant effects on LDL‐, HDL‐ or total cholesterol levels. The lower plasma TAG concentration was consistent with the reduced/delayed digestion and absorption of TAG with the AXRF (total fatty acid and MUFA p < 0.01; unsaturated fatty acid p < 0.05). Conclusion: The results suggest that AXRF reduced the levels of circulating BAs which slowed down the digestion of TAG and absorption of free fatty acids, with consequent reduction in blood TAG. Reduction in circulating bile acids by arabinoxylan causes reduction in lipids digestion and absorption.