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

J Am Assoc Nurse Pract. 2017 Apr;29(4):216-223. doi: 10.1002/2327-6924.12447. Epub 2017 Mar 2.


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.

Publication types

  • Review

MeSH terms

  • Dietary Fiber / pharmacology
  • Dietary Fiber / therapeutic use*
  • Dietary Supplements / standards*
  • Glucans / pharmacology
  • Glucans / therapeutic use
  • Humans
  • Intestine, Small / physiology
  • Inulin / pharmacology
  • Inulin / therapeutic use
  • Metabolism / drug effects*
  • Metabolism / physiology*
  • Psyllium / pharmacology
  • Psyllium / therapeutic use
  • beta-Glucans / pharmacokinetics
  • beta-Glucans / therapeutic use


  • Dietary Fiber
  • Glucans
  • beta-Glucans
  • Psyllium
  • Inulin
  • polydextrose