Serum lipid and fecal bile acid changes with cereal, vegetable, and sugar-beet fiber feeding

Thirty-four subjects consumed six controlled formula diets for 3 wk each, supplemented with 0 g added fiber, 10 and 30 g dietary fiber as wheat bran (WB), 10 and 30 g dietary fiber as mixed vegetable fiber (VF), and 30 g dietary fiber as sugar-beet fiber (SBF). Serum cholesterol changes for fiber free, 10 g WB, 30 g WB, 10 g VF, 30 g VF, and 30 g SBF (-0.13, -0.18, -0.05, -0.17, -0.24, and -0.70 mmol/L, respectively) were significant for 30 g VF and 30 g SBF. Reduction in total cholesterol with SBF was largely due to significant lowering of low-density-lipoprotein cholesterol. Total fecal bile acid concentrations were significantly higher with the fiber-free diet than with 30 g WB, VF, and SBF (P less than 0.001) and were also higher with 30 g SBF than with 30 g WB and 30 g VF (P less than 0.005). Daily fecal bile acid excretion was not different on 30 g SBF compared with 30 g WB and 30 g VF. Differences in cholesterol reduction across the diets could not be explained by differences in fecal bile acid excretion.