Effects of elaidic acid on plasma cholesterol and gut microbiota in hypercholesterolemic hamsters

This study aimed to evaluate the effects of elaidic acid (EA) on plasma cholesterol levels and gut microbiota composition in hypercholesterolemic hamsters The EA treatment group consisted of two doses, the low-dose diet contains 0.45% EA, while the high-dose diet contains 1.80% EA. A total of 32 male hamsters were randomly assigned to four dietary groups (n = 8 per group): a cholesterol-free control diet (NCD), a high-cholesterol diet (HCD), a high-cholesterol diet supplemented with 0.45% EA (LT), and a high-cholesterol diet supplemented with 1.80% EA (HT). The results showed that the high-density lipoprotein cholesterol (HDL-C) level was significantly reduced by 7.7% in the high-dose EA feeding group. EA supplementation significantly increased fecal excretion of total neutral sterols and coprostanol, while reducing fecal cholesterol output. Addition of EA in diet did not affect the excretion of total fecal bile acids but it significantly increased the primary bile acid excretion with a concurrent significantly reduction in the secondary bile acid excretion in the HT dietary group compared with HCD hamsters. This shift in bile acid profile was accompanied by a notable reduction in the production of key short-chain fatty acids (SCFAs). Dietary EA caused a marked elevation of the Firmicutes/Bacteroidetes ratio with a notable decrease in the relative abundance of Bacteroidaceae and Clostridiales. It was therefore concluded that EA feeding could reduce plasma HDL-C, cause gut microbiota dysbiosis, and reduce the production of fecal SCFAs.