Timm, Derek Allen2013-01-312013-01-312012-09https://hdl.handle.net/11299/143797University of Minnesota Ph.D. dissertation. September 2012. Major: Nutrition. Advisor: Dr. Joanne Slavin. 1 computer file (PDF); ix, 109 pages.Dietary fiber from whole foods has long been known to regulate bowel function; however it is essential to confirm this in isolated or synthesized fibers. Stool weight, gastrointestinal transit time, and stool consistency are all ways to measure changes in bowel function in humans and can be used to evaluate the efficacy of dietary fibers. Gastrointestinal tolerance is also of great concern since consumer acceptability of dietary fiber is related to intolerance issues. Furthermore, since observational and epidemiological data suggests dietary fiber reduces energy intake, which may be modulated by changes in postprandial satiety, we also investigated acute satiety using visual analog scale (VAS) and food intake via food diaries. Therefore, we investigated the influence of 20 grams per day for 10 days of the functional fibers Polydextrose (PDX) and Soluble Corn Fiber (SCF) compared a low fiber control on bowel function. Thirty-six healthy men and women completed this randomized, double-blind, placebo-controlled study. A two-week washout period was completed between each treatment period. Results show both PDX and SCF significantly increased stool weight compared to the control treatment. In contrast, whole gut transit time was not difference among the treatments. Stool pH was significantly lower for PDX compared to the control treatment. PDX caused a significantly looser stool than SCF and control. Flatulence and stomach noises were significantly increased by the fiber treatments compared to the control. Satiety was not difference among the treatments as measured by a VAS. No differences were observed in energy intake among the treatments.en-USLaxationPolydextroseSatietyShort-chain fatty acidSoluble corn fiberToleranceThesis or Dissertation