In this study we analyzed a commercial dietary fiber blend known as Fiber-Plus and a dietary fiber mixture (DFM) prepared in our lab (10% apple pectin, 10% orange pectin, 36% locust bean gum and 44% corncob composed of 56% fiber). DFM provided greater inhibition of starch digestion and glucose absorption (p < 0.05) than did Fiber-Plus. DFM was also found to be significantly more efficient (p < 0.05) than Fiber-Plus at reducing the glycemic response following starch loading. Rats fed DFM or corncob demonstrated a much lower glycemic response following a test meal as compared to those fed a fiber-free diet. Both fiber sources decreased fasting cholesterol and triglyceride concentrations; transit time was shortened and fecal values were higher than those of controls. beta-glucuronidase activity in intestinal segment contents and feces was lower in rats fed fiber. We conclude that DFM is effective in controlling plasma glucose and lipid levels. Corncob, a novel fiber source, could be beneficial in the treatment of gastrointestinal tract disorders and in the elimination of carcinogenic elements.