Defining dietary plant fibers in human nutrition.

Research on the nutritional aspects of dietary plant fibers in human nutrition has been plagued by many problems of definition, terminology, analytical procedures, as well as insufficient consideration of the interactions of other dietary components with the dietary fiber polymers. The use of the term non-nutritive has also led to some confusion, as many polymers of dietary fiber are digested by intestinal bacteria in humans. It appears extremely important for the orderly progress of this field that comprehensive terms be used cautiously and that perhaps a new umbrella term (such as plantix) should be introduced. The physiological effects of various polymers have been shown to differ considerably; thus the effect of dietary fiber should not be generalized. Analytical procedure should include both water-insoluble and water-soluble fractions and some consideration should be given to the non-polymeric, enzyme-indigestible compounds such as certain seed and leaf waxes.