Low‐digestible carbohydrates and bowel function

Abstract

Low-digestible carbohydrates (LDC) include dietary fiber, resistant starch and polyols. The incomplete digestion, absorption and subsequent colonic fermentation and/or fecal excretion of LDC have been shown to confer health benefits, including gut acidification, short chain fatty acid production, improved laxation and alterations in colonic microflora. Most Americans consume less than half the recommended amount of dietary fiber daily (38 grams for men), but less information is available on intake of other LDC. Therefore, we examined published feeding studies of fibers (guar gum, inulin fructans and poydextrose), resistant starch and polyols and gastrointestinal function data in healthy and diabetic subjects. We found many LDC are tolerated well in daily doses of 40–50 grams. However, the given LDC, individual characteristics and conditions of intake affect tolerance. In general, LDC are better tolerated when incorporated into solid foods in meals than when in hydrated forms on an empty stomach. As the prevalence of LDC in the food supply increases, more studies are needed that allow for direct comparisons between different LDC and that consider subjects’ usual LDC intake and total LDC intake during a study. Also, since LDC all provide similar gastrointestinal benefits, recommendations for dietary fiber intake should expand to include other LDC such as resistant starch and polyols.