Digestion of non-starch polysaccharides by non-ruminant omnivores

Abstract

The definition of fibre, particularly in the context of foods eaten by man, is still controversial. For the purposes of the present paper, a reductionist view will be taken and fibre considered to be non-starch polysaccharides (NSP), since in making digestibility measurements a definition is required which can be translated into an analytical method suitable for use with foods and faeces. This reductionist approach ignores many other food components including starches resistant to pancreatic amylase, oligosaccharides, lactose (for most animals and man post weaning), some protein and lipid fractions (Cummings & Englyst, 1987) and organic anions such as oxalate and tartrate (Florin et al. 1990) which, in the large intestine (LI), behave similarly to some NSP and might be included within the definition of fibre by those taking an holistic view. However, there is little quantitative information on the amounts of these fractions in foods or their sites and extents of digestion so that the restricted definition of fibre is justified at present.