Physiologic Effects of Isolated or Synthetic Dietary Fiber in Children: A Scoping Review

Linfei Chen; Esther A Avendano; Angelica Valdes-Valderrama; Jessie L Lan; Dominique Tye; Rebecca A Morin; Kara A Staffier; Nicola M McKeown; Nanguneri Nirmala

doi:10.1016/j.cdnut.2023.102074

Physiologic Effects of Isolated or Synthetic Dietary Fiber in Children: A Scoping Review

Curr Dev Nutr. 2024 Jan 4;8(2):102074. doi: 10.1016/j.cdnut.2023.102074. eCollection 2024 Feb.

Authors

Linfei Chen¹, Esther A Avendano², Angelica Valdes-Valderrama³, Jessie L Lan³, Dominique Tye³, Rebecca A Morin⁴, Kara A Staffier⁵, Nicola M McKeown⁶, Nanguneri Nirmala²

Affiliations

¹ Tufts University School of Medicine, Boston, MA, United States.
² Institute for Clinical Research and Health Policy Studies, Center for Clinical Evidence Synthesis, Tufts Medical Center, Boston, MA, United States.
³ Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, United States.
⁴ Hirsh Health Sciences Library, Tufts University, Boston, MA, United States.
⁵ American College of Life Style Medicine, Chesterfield, MO, United States.
⁶ Department of Health Sciences, Sargent College of Health and Rehabilitation Sciences, Boston University, Boston, MA, United States.

Abstract

Background: Fiber is an integral part of a healthy diet. Studies have shown that the fiber intake in children is below adequate amounts, leading to adverse health outcomes.

Objectives: This study aimed to perform a scoping review to assess the available evidence for the impact of isolated and synthetic dietary fiber on children's health outcomes.

Methods: A systematic literature search was conducted in Ovid Medline, Ovid Global Health, Embase, and Cochrane Library via Wiley to identify randomized controlled trials (RCTs) in healthy children aged 1-18 y at baseline who consumed added, isolated, or synthetic dietary fiber. The outcomes of interest were categorized based on the Food and Drug Administration's guidance for industry on nondigestible carbohydrates and the Vahouny Fiber Symposium criteria, which included reduced fasting blood, glucose, total and/or LDL cholesterol concentrations, attenuation of postprandial glycemia/insulinemia, increased fecal bulk/laxation, reduced transit time, weight loss/reduction in adiposity, reduced energy intake from food consumption, increased satiety, bone health/enhanced mineral absorption, and blood pressure. We also cataloged additional reported outcomes.

Results: Of 3837 randomized controlled parallel or crossover trials screened at the abstract level, 160 were eligible for full-text review, and 32 included for data extraction. This scoping review presents analysis of data from 32 RCTs in children who were healthy, overweight/obese or had mild hypercholesterolemia. Inulin-type fructans (41%) and psyllium (22%) were the most frequently administered fiber types, with weight/adiposity, markers of lipid metabolism (41%), and bone-related markers (38%) being the most frequently reported health outcomes. Only a few RCTs have investigated the effects of laxation (9%), and none specifically studied the impact of fiber on reducing postprandial glycemia/insulinemia.

Conclusions: This scoping review demonstrates sufficient evidence for conducting systematic reviews and meta-analyses for several outcomes. Evidence gaps remain on the impact of isolated fibers on outcomes such as laxation, colonic transit time, and postprandial glycemia/insulinemia in children.

Keywords: child health; dietary fiber; inulin-type fructans; isolated fiber; psyllium; scoping review; synthetic fiber.