EFFECT OF DIFFERENT VARIETIES OF PECTIN AND GUAR GUM ON PLASMA, HEPATIC AND BILIARY LIPIDS AND CHOLESTEROL GALLSTONE FORMATION IN HAMSTERS FED ON HIGH-CHOLESTEROL DIETS

The effect of high- (hePE) and low- (lePE) esterification pectin and h igh- (hvGG) and low- (lvGG) viscosity guar gum on plasma, hepatic and biliary lipids and on prevention of cholesterol gallstones was investi gated in male golden Syrian hamsters (Mesocricetus auratus). Hamsters were fed on cholesterol-rich (4 g/kg), gallstone-inducing diets far 6 weeks. The diets were supplemented with 80 g hePE, lePE, hvGG or lvGG/ kg or 80 g additional cellulose/kg. No significant differences in plas ma total cholesterol and triacylglycerol concentrations between hvGG a nd lvGG and the gallstone-inducing or cellulose-enriched diets were ob served. The hePE diet produced a 16% (non-significant) reduction in to tal plasma cholesterol but significantly decreased the plasma triacylg lycerol level by 45%. The lePE diet caused only minor changes in plasm a lipids. Hepatic cholesterol concentrations were significantly higher in hamsters fed on hvGG, lvGG, hePE or lePE primarily due to the accu mulation of esterified cholesterol. Supersaturated bile samples, with lithogenic indices ranging from 1.6 to 2.0, were determined with all d iets. The hePE and lePE diets slightly altered the bile acid profile b y increasing glycocholic acid and decreasing taurochenodeoxycholic aci d concentrations resulting in a higher cholic :chenodeoxycholic acid r atio. Cholesterol gallstone formation was not substantially inhibited by the two varieties of pectin and guar gum. The hvGG, lvGG, hePE and lePE diets did not alter faecal weight and caused only minor increases in faecal bile acid excretion. In general, the present findings demon strate that dietary pectins and guar gums had only minor effects on ch olesterol metabolism and did not prevent cholesterol gallstone formati on in this hamster model. Possible explanations for this lack of a dis tinct response to pectin and guar gum are discussed.