16-4

B. TUNGLAND, Vice President, Scientific and Regulatory Affairs, Imperial Sensus, 8016 Highway 90A, Sugarland, TX 77478

Non-digestible, non-starch polysaccharides (NSP) and non-digestible oligosaccharides (NDO) occur naturally in many foods, mainly in fruits, vegetables, and whole grains. The physicochemical and biological properties of these compounds, as they relate to soluble fiber, are primarily associated with physiological functions in the small and large intestine, having important implications in human health.

These properties include dispersibility and solubility in water, viscosity effects, absorption, and fermentability and binding of other compounds. Some NSP possess properties of water dispersion and increased viscosity in the small intestine that are associated with slowing digestion, the absorption of digestible carbohydrates and lipids, and promoting nutrient absorption over a greater length of the small intestine. These physiological actions relate specifically to both lipid and glucose attenuation.

In addition to these viscosity-inducing NSP, such as guar gum, other NSP (such as inulin) and NDOs do not appear to increase viscosity significantly. However, these low-viscosity carbohydrates play an important role in maintaining gastrointestinal health as selective fermentation substrates for health-promoting lactic-acid-producing bacteria. Through their selective fermentation and short-chain fatty production, these non-digestible carbohydrates, particularly the inulins, have been shown to influence morphology and function of the colon and have positive influences on carbohydrate and lipid metabolism, calcium bioavailability, and immune function. Consumption of NSP and NDO have been associated with reductions in plasma and LDL-cholesterol, glucose and insulin attenuation, or laxation (increased fecal bulk and softening).

These physiological responses are the primary basis for reduced risks of several chronic diseases such as cardiovascular disease (CVD), diabetes, and colon cancers. In addition, the selective or prebiotic effects of the inulins may further help reduce the risk of developing osteoporosis, autoimmune diseases, foodborne hypersensitivities, opportunistic infections such as yeasts, and several gastrointestinal disorders.