<P> Dietary fiber may act on each phase of ingestion, digestion, absorption and excretion to affect cholesterol metabolism, such as the following: </P> <Ol> <Li> Caloric energy of foods through a bulking effect </Li> <Li> Slowing of gastric emptying time </Li> <Li> A glycemic index type of action on absorption </Li> <Li> A slowing of bile acid absorption in the ileum so bile acids escape through to the cecum </Li> <Li> Altered or increased bile acid metabolism in the cecum </Li> <Li> Indirectly by absorbed short - chain fatty acids, especially propionic acid, resulting from fiber fermentation affecting the cholesterol metabolism in the liver . </Li> <Li> Binding of bile acids to fiber or bacteria in the cecum with increased fecal loss from the entero - hepatic circulation . </Li> </Ol> <Li> Caloric energy of foods through a bulking effect </Li> <Li> Slowing of gastric emptying time </Li>

State the differences between dietary fiber and crude fiber