Polydextrose and soluble corn fiber significantly increase stool weight, but do not influence whole gut transit time in healthy adults

This study examined the effects of consuming 20 g daily of polydextrose or soluble corn fiber on gastrointestinal function in healthy adults. Laxation, defined as the ability to significantly increase stool weight, is one of the accepted criteria to classify novel carbohydrates as fiber. Therefore, we conducted gender‐balanced placebo controlled three‐period crossover study to examine the laxation effects of polydextrose and soluble corn fiber. Subjects (n = 36) consumed 20 grams of study supplement daily for 10 days during each of three periods. Subjects swallowed a single dose of 20 radioopaque markers on day 6 and then collected fecal samples for the last 5 days of each treatment. Stool wet weight, number of stools, and whole gut transit time were determined. Data were analyzed using the mixed procedure of SAS with significance achieved at p < 0.05. Polydextrose and soluble corn fiber increased 5‐day stool wet weight compared to control (p < .05), and increased total number of stools during the 5‐day sampling period by 1 and 0.9 respectively compared to the control (p < .001). No differences in whole gut transit time were observed. This study demonstrates a clear laxation benefit of polydextrose and soluble corn fiber at a 20 gram per day dose. This study was supported by General Mills Inc. and Tate & Lyle Health & Nutrition Sciences. Grant Funding Source : General Mills and Tate & Lyle