Fiber supplements and clinically proven health benefits: How to recognize and recommend an effective fiber therapy

Abstract

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.

Figure 1

The glycemic effects over time for a 6‐month study in patients with metabolic syndrome. The controlled diet alone failed to show a sustained effect versus baseline. The addition of psyllium to the controlled diet showed improvement in glycemic measures throughout the 6‐month study.