American Journal of Clinical Nutrition, Vol 68, 615-622, Copyright © 1998 by The American Society for Clinical Nutrition, Inc

ORIGINAL RESEARCH COMMUNICATIONS

Increasing amounts of dietary fiber provided by foods normalizes physiologic response of the large bowel without altering calcium balance or fecal steroid excretion

VS Haack, JG Chesters, NW Vollendorf, JA Story and JA Marlett
Department of Nutritional Sciences, University of Wisconsin-Madison, 53706, USA.

Nine healthy, young men consumed constant diets to determine selected large-bowel, serum cholesterol and triacylglycerol, and calcium balance responses to 3 amounts of fiber provided by a mixture of fruit, vegetables, and grains. The diets, each consumed for 1 mo, contained 16, 30, and 42 g total fiber/d, of which 2.9, 4.8, and 7.7 g, respectively, was soluble. Mean daily wet and dry stool weights increased with each fiber addition. The first fiber addition increased defecation frequency and decreased fecal pH, bile acid concentration, and neutral steroid concentration; the second addition had no further effect. Mean weight of each defecation and stool moisture did not increase and serum cholesterol and triacylglycerol concentrations, calcium balance, and gastrointestinal transit time did not decrease as fiber intake increased. We conclude that 1) fiber provided by a mixed- food diet increases stool weight as effectively as does wheat or oat bran; 2) even high amounts of dietary fiber do not change transit time or defecation frequency if they are already approximately 1 and 2-3 d, respectively; 3) food patterns consistent with the food pyramid and incorporating legumes and whole grains are necessary to achieve recommended fiber intakes of 20-35 g/d, even if energy intake is > 12.55 MJ (3000 kcal); 4) soluble fiber provided by a mixture of whole foods has no effect on serum cholesterol concentrations or output of fecal bile acids; and 5) mixed-food fiber has little effect on calcium balance when calcium intakes are high (> or = 1.5 g/d).

This article has been cited by other articles:

				J. A Marlett, T. M Kajs, and M. H Fischer An unfermented gel component of psyllium seed husk promotes laxation as a lubricant in humans Am. J. Clinical Nutrition, September 1, 2000; 72(3): 784 - 789. [Abstract] [Full Text] [PDF]

				S.'i. Kurasawa, V. S. Haack, and J. A. Marlett Plant Residue and Bacteria as Bases for Increased Stool Weight Accompanying Consumption of Higher Dietary Fiber Diets J. Am. Coll. Nutr., August 1, 2000; 19(4): 426 - 433. [Abstract] [Full Text] [PDF]

				M.P. Vaquero, L. Perez-Olleros, M. Garcia-Cuevas, M. Veldhuizen, B. Ruiz-Roso, and A. Requejo Mineral absorption of diets containing natural carob fiber compared to cellulose, pectin and various combinations of these fibers Absorcion de minerales de dietas que contienen fibra natural de algarrobas comparada con celulosa, pectina y varias combinaciones de estas fibras Food Science and Technology International, January 1, 2000; 6(6): 463 - 471. [Abstract] [PDF]