Effects of Dietary Pectin, Tangerine Pulp Meal, Propionate, Lactate or Fumarate on Serum and Liver Cholesterol Levels, and Dietary Pectin on Cholesterol Absorption in Bats

The effect of dietary pectin, tangerine pulp meal, propionate, lactate or fumarate on cholesterol (C) and triacylglycerol(TG) levels in the serum and liver, and the effect of pectin on dietary C absorption were studied in a series of three experiments. Mature female Sprague Dawley rats were fed a control diet or diets containing 5% pectin, 5% tangerine pulp meal, 3% propionate, 3% lactate 3% fumarate, or 10% pectin. Serum total C levels were lower(p<0.05) in rats fed the diet containing 5% pectin than in control rats after a 4-week feeding period(93.8 vs 119.2mg/100mL). Serum HDL, LDL+VLDL C levels were not different among diet groups. Liver total C level was also lower(p<0.05) in rats fed the diet containing 5% pectin than in control rats, but liver TG level was not influenced by diet. Dietary propionate, lactate or fumarate did not reduce serum C, indicating that propionate is not a regulator of serum C. However, dietary pectin(10%) increased fecal excretion of dietary C(or its metabolites) more than 70% over a control value. Our data indicate that dietary pectin reduces serum and liver C levels by increased fecal secretion of dietary C, but not by its fermentation product propionate or other gluconeogenic substrates. (Korean J Nutrition 31(5) : 914∼920, 1998)