Background: Only 5% of adults consume the recommended level of dietary fiber. Fiber supplements appear to be a convenient and concentrated source of fiber, but most do not provide the health benefits associated with dietary fiber.
Purpose: This review will summarize the physical effects of isolated fibers in small and large intestines, which drive clinically meaningful health benefits.
Data sources: A comprehensive literature review was conducted (Scopus and PubMed) without limits to year of publication (latest date included: October 31, 2016).
Conclusions: The physical effects of fiber in the small intestine drive metabolic health effects (e.g., cholesterol lowering, improved glycemic control), and efficacy is a function of the viscosity of gel-forming fibers (e.g., psyllium, β-glucan). In the large intestine, fiber can provide a laxative effect if (a) it resists fermentation to remain intact throughout the large intestine, and (b) it increases percentage of water content to soften/bulk stool (e.g., wheat bran and psyllium).
Implications for practice: It is important for nurse practitioners to understand the underlying mechanisms that drive specific fiber-related health benefits, and which fiber supplements have rigorous clinical data to support a recommendation.
Clinical pearl: For most fiber-related beneficial effects, "Fiber needs to gel to keep your patients well."
Keywords: Dietary fiber; advanced practice nurse; large intestine; nurse practitioner; small intestine; therapeutics; viscosity.
©2017 The Authors. Journal of the American Association of Nurse Practitioners published by Wiley Periodicals, Inc. on behalf of American Association of Nurse Practitioners.