Dietary Soluble Fiber and Cholesterol Affect Serum Cholesterol Concentration, Hepatic Portal Venous Short-Chain Fatty Acid Concentrations and Fecal Sterol Excretion in Rats

Abstract

Sprague-Dawley rats were fed diets containing 7.5% dietary fiber as cellulose (control), pectin, psyllium or oat bran with or without 0.3% added cholesterol for 3 wk. Among rats fed cholesterol, liver total lipid and cholesterol concentrations were significantly lower in groups fed pectin, psyllium and oat bran compared with cellulose-fed controls. Cholesterol feeding resulted in significantly greater liver cholesterol in rats fed cellulose, psyllium and oat bran but not in those fed pectin. Among rats fed cholesterol, total serum cholesterol levels were significantly lower in those fed pectin than in those fed psyllium, oat bran or cellulose. When cholesterol was fed, the oat bran-fed group had significantly higher butyrate and the pectin-fed group had significantly higher propionate concentrations in the hepatic portal vein than did cellulose-fed controls. The groups fed psyllium, oat bran and pectin all had significantly higher fecal neutral sterols than did the cellulose-fed group when cholesterol was fed. Without dietary cholesterol only pectin-fed rats had significantly higher fecal excretion of neutral sterols than those fed cellulose. Dietary fiber did not influence fecal acidic sterol excretion. However, the addition of cholesterol to these fiber diets was accompanied by a significantly higher bile acid excretion than that of animals fed cellulose without cholesterol. The results of this study indicate that soluble dietary fibers may exert their hypocholesterolemic effect by increasing excretion of fecal neutral sterols.

Effects of Dietary Fiber Prepared from Sweet Potato Pulp on Cecal Fermentation Products and Microflora in Rats

“…It is reported 5,21) that the propionate prevents the synthesis of a cholesterol because it inhibits the HMG CoA synthase, the HMG CoA reductase and the acetyl CoA synthetase activities. There are some conflicts between propionate concentration and choresterol synthesis in vivo.…”

Dietary approaches for management of cardio-vascular health- a review

“…The hypocholesterolemic effects of psyllium (Olson et al 1997), guar gum (Todd et al 1990) and oat bran (Ripsin et al 1992) are well documented by meta -analyses. Animal studies have consistently shown that fibres that reduce plasma cholesterol increase neutral sterol or bile acid excretion (Illman and Topping 1985;Kritchevsky 1988;Arjmandi et al 1992). Many large epidemiological studies such as Nurses' Health Study and Scottish Heart Health Study have demonstrated a reduced risk for CHD in both men and women who consume higher amounts of dietary fibre (Anderson and Hanna 1999;Todd et al 1999;Wolk et al 1999).…”

Comparação entre o efeito do resíduo do abacaxizeiro (caules e folhas) e da pectina cítrica de alta metoxilação no nível de colesterol sangüíneo em ratos

“…Já os resultados apresentados concordaram com os resultados de ROSA et al [33,34] e SHINNICK et al [35], de fibras mistas de feijões e farelo de aveia, respectivamente. Para as dietas com pectina os resultados estão de acordo com os estudos de ARJMANDI et al [7,8] …”

“…Este comportamento pode ser atribuído ao caráter hidrofílico de certas fibras, como as pectinas e as gomas, que fazem com que a taxa de esvaziamento gástrico seja mais lenta, aumentando a saciedade, e conseqüentemente reduzindo a ingestão de alimentos [15]. O presente trabalho promoveu redução no ganho de peso dos animais alimentados com as dietas acrescidas de pectina em relação à dieta controle, concordando com os trabalhos de ARJMANDI et al [7,8] que pesquisaram pectina, psyllium e farelo de aveia. Porém, discorda dos resultados apresentados por AL-OTHMAN et al [2]; JIMENEZ-VERGARA et al [21] e YAMADA et al [40], os quais pesquisaram a goma arábica, pectina e a goma guar, respectivamente.…”

“…Entre os tratamentos com 10% e 15% de pectina não houve diferença significativa. Resultados obtidos por AL-OTHMAN et al [2], ARJMANDI et al [7,8], ANDERSON et al [6], YAMADA et al [40] e JIMENEZ-VERGARA et al [21], demonstraram que a pectina reduz os níveis séricos do colesterol total nos animais. Entre os tratamentos acrescidos com o resíduo do abacaxizeiro, a dieta com 10% de resíduo promoveu uma redução de 12% em relação à dieta controle; já as demais não apresentaram diferença.…”