RESUMEN
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, ß-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."
