Effects of Cereal, Fruit and Vegetable Fibers on Human Fecal Weight and Transit Time: A Comprehensive Review of Intervention Trials.

Jan De Vries,Kristin Verbeke,Kernon Gibes,Toine Hulshof,Anne Birkett

doi:10.3390/nu8030130

Abstract

Cereal fibers are known to increase fecal weight and speed transit time, but far less data are available on the effects of fruits and vegetable fibers on regularity. This study provides a comprehensive review of the impact of these three fiber sources on regularity in healthy humans. We identified English-language intervention studies on dietary fibers and regularity and performed weighted linear regression analyses for fecal weight and transit time. Cereal and vegetable fiber groups had comparable effects on fecal weight; both contributed to it more than fruit fibers. Less fermentable fibers increased fecal weight to a greater degree than more fermentable fibers. Dietary fiber did not change transit time in those with an initial time of <48 h. In those with an initial transit time ≥48 h, transit time was reduced by approximately 30 min per gram of cereal, fruit or vegetable fibers, regardless of fermentability. Cereal fibers have been studied more than any other kind in relation to regularity. This is the first comprehensive review comparing the effects of the three major food sources of fiber on bowel function and regularity since 1993.

Highlights

Dietary fiber has well-known beneficial effects on human regularity, increasing fecal weight and transit time [1,2]
The snowball method identified 71 other studies. We excluded those with unhealthy populations, The analysis of fermentability and total fecal wet weight and transit time is based on 206 and leaving 65 intervention trials for the analysis
Outcomes from this study show that estimated fermentability determines the role of fiber in total fecal wet weight

Summary

Introduction

Dietary fiber has well-known beneficial effects on human regularity, increasing fecal weight and transit time [1,2] Both fecal weight and transit time are key indicators of intestinal and digestive health [3]. Dietary fiber plays an important role in the adequate function of the gastrointestinal tract [7] and has been advocated for improved bowel function since the early 1970s [8]. That it improves nutrition and health is without dispute [9]. As heterogeneous groups of compounds with unique and overlapping functions, dietary fibers optimize health and provide the best outcomes when they complement and augment each other [9]

Methods

Results

Conclusion