Guar gum consumption in regulation of enterohepatic cholesterol metabolism in pigs fed a high fat diet

Thumbnail Image
Rideout, Todd Christopher
Journal Title
Journal ISSN
Volume Title
University of Guelph

This thesis investigates the hypocholesterolemic actions of guar gum (GG) by examining the expression of genes that regulate the enterohepatic circulation of cholesterol in pigs fed a high-fat control diet or the control diet supplemented with 10% GG. In comparison with the control group, GG consumption reduced intestinal cholesterol absorption by 59%, increased cholesterol loss from the distal ileum by 138%, and reduced plasma total cholesterol and low-density lipoprotein (LDL) cholesterol concentrations by 27 and 37%, respectively. Within the liver, GG consumption increased hepatic low-density lipoprotein receptor (LDLr) mRNA and protein expression, enhanced the protein abundance of the cytoplasmic precursor and nuclear active forms of sterol regulatory element binding protein 2 (SREBP2), and increased the mRNA and protein expression of hepatic ATP-binding cassette transporters G5 and G8 (ABCG5/G8) in comparison with the control group. We conclude that the hypocholesterolemic effects of GG consumption are mediated by a reduction in intestinal cholesterol absorption, a SREBP2-dependent increase in hepatic LDLr, and an enhanced cholesterol loss from the distal ileum.

guar gum, pigs, high fat diet, enterohepatic cholesterol metabolism, liver