title: Dietary fiber type reflects physiological functionality: comparison of grain fiber, inulin, and polydextrose.
abstract: Dietary fiber is a nutritional concept based not on physiological functions but on defined chemical and physical properties. Recent definitions of dietary fiber differentiate inherent plant cell wall-associated fiber from isolated or synthetic fiber. For the latter to be defined as fiber, beneficial physiological effects should be demonstrated, such as laxative effects, fermentability, attenuation of blood cholesterol levels, or postprandial glucose response. Grain fibers are a major natural source of dietary fiber worldwide, while inulin, a soluble indigestible fructose polymer isolated from chicory, and polydextrose, a synthetic indigestible glucose polymer, have more simple structures. Inulin and polydextrose show many of the same functionalities of grain fiber in the large intestine, in that they are fermentable, bifidogenic, and laxative. The reported effects on postprandial blood glucose and fasting cholesterol levels have been modest, but grain fibers also show variable effects. New biomarkers are needed to link the physiological functions of specific fibers with long-term health benefits.
authors.affiliation: Food and Health Research Centre, Department of Clinical Nutrition, University of Eastern Finland, Kuopio, Finland.
authors.forename: Kaisa
authors.initials: K
authors.lastname: Raninen
authors.forename: Jenni
authors.initials: J
authors.lastname: Lappi
authors.forename: Hannu
authors.initials: H
authors.lastname: Mykkänen
authors.forename: Kaisa
authors.initials: K
authors.lastname: Poutanen
mesh_terms: D004043:Dietary Fiber / Q000378:metabolism*; D004068:Digestive System Physiological Phenomena; D005936:Glucans / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007444:Inulin / Q000737:chemistry / Q000378:metabolism*; D012995:Solubility
chemical_list: D004043:Dietary Fiber; D005936:Glucans; D007444:Inulin; C033375:polydextrose