Dose-Responsive Effect of Polydextrose on Whole Gut Transit Time

Inclusion Criteria: * Age between 18 and 70 years * Body mass index between 18.5 and 29.9 kg/m2 (encompasses normal weight and overweight) * Meets the Rome III criteria for functional constipation as follows: (Criteria fulfilled for the last 3 months with symptom onset at least 6 months prior to diagnosis): Must meet 2 or more of the following criteria: * Straining during at least 25% of defecations * Lumpy or hard stools in at least 25% of defecations * Sensation of incomplete evacuation for at least 25% of defecations * Sensation of anorectal obstruction/blockage for at least 25% of defecations * Manual maneuvers to facilitate at least 25% of defecations (e.g., digital evacuation, support of the pelvic floor) * Fewer than three defecations per week * Loose stools are rarely present without the use of laxatives * Insufficient criteria for irritable bowel syndrome * Ability of the participant (in the investigator's opinion) to comprehend the full nature and purpose of the study including possible risks and side effects * Consent to the study and willing to comply with study product and methods * Willingness to maintain a stable diet throughout the study * Consistent use and dose of chronic medication, if any, in the past 30 days Exclusion Criteria: * Major gastrointestinal complication (e.g. Crohn"s disease, colitis, celiac disease) * Febrile diverticulitis within 1 year of screening * Pelvic floor dysfunction * Prior abdominal surgery that in the opinion of the investigator may present a risk for the subject or confound study results * Prior abdominal surgery of the following type: gastric bypass, lap band, colectomy, removal of gall bladder * Clinically significant underlying systemic illness that may preclude the subject"s ability to complete the trial or that may confound the study outcomes * Any clinically relevant abnormalities in the physical examination or in laboratory variables before entry into the study * Daily consumption of probiotics, prebiotics, fermented milk, and/or yogurt within 2 weeks of screening * Laxative, fiber supplement, or other constipation medication (e.g. prokinetic drugs) use within 2 weeks of screening * Antibiotic use within 1 month of enrollment * Regular use of any drug or dietary supplement known to cause constipation (e.g. iron, opioids, sucralfate, misoprostol, 5-HT#- antagonists, antacids with magnesium or aluminum, or diarrhea medication) * Anticipated major dietary or exercise changes during the study period * Known allergies to any substance in the study product * Pregnant or lactating female, or pregnancy planned during study period * Eating disorder * History of alcohol, drug, or medication abuse * Participation in another study with any investigational product within 3 months of screening * Investigator believes that the participant may be uncooperative and/or noncompliant and should therefore not participate in the study