The experimental design was a 7-week clinical trial study, which consisted of a one-week screening period followed by a 3-week supplementation period with GMP protein powder and a 3 week-washout period.
Participants were recruited by using flyers posted across email listservs (the pool from the Center for Sensory & Consumer Behavior Research, Oregon State University (OSU, Department of Food Science and Technology, OSU’s email news briefing (OSU Today), OSU College of Public Health and Human Science news briefing and were also be posted locally around the OSU campus. Potential subjects who contacted study coordinators were screened for eligibility and were interested in continuing were met in person for written informed consent. Potential subjects who contacted study coordinators were screened for eligibility against the following criteria through a screening questionnaire and follow-up in-person interview: subjects must be between the ages of 18 and 30 and have IBS diagnosis, and subjects must not have lactose or dairy intolerance or allergy, any known gastrointestinal disease or disorder beyond IBS or major gastrointestinal surgery, habitual use of laxatives or antacids, use of antibiotics within one month prior to the study, or use of prebiotics or probiotics within one month prior to the study. Any subject who, in the physician's opinion, had a medical or psychological condition that would preclude them from completing the study would not be included. A total of 5 adults (1 male and 4 females), ages 20 - 23 years (mean:21.2 years; standard deviation: 1.10 years) participated in the clinical trial. During the study, participants continued with the normal diets that they recorded weekly in a food frequency questionnaire. The only dietary restrictions were no pre/probiotic supplements and antibiotics.
