B. Lactis B94 Effects of Gastrointestinal Function

Probiotics have been shown to improve symptoms of constipation by decreasing gastrointestinal transit time, increasing stool frequency, and normalizing stool form. A 20-week randomized, double-blinded, placebo-controlled crossover study will be carried out. Participants will complete a 4-week baseline period during which stool frequency, stool consistency (transit time), and gastrointestinal symptoms will be collected by paper questionnaire, and participants will collect a single stool. Dietary intake data (3-day) will be obtained during the baseline period. Participants will be randomized on or about day 29 and will consume Bifidobacterium animalis ssp lactis B94 (B. lactis B94) or placebo for 4 weeks, followed by a 4-week washout, 4 weeks on the alternative, and second 4-week washout. Participants will be randomized by sealed envelope method, prepared by a UF faculty member not affiliated with the study.

During the intervention and washout periods, participants will complete daily questionnaires to assess stool frequency and form (Bristol Stool Form Scale). Furthermore, they will complete Gastrointestinal Symptom Rating Scale (GSRS) at weeks 4, 8, 12, 16 and 20(± 3 days). During these same weeks (± 3 days) dietary intake data (28-day record) and stools will be collected (1 per period). Participants' height and weight will be taken at baseline, and weight during weeks 4, 8, 12, 16 and 20.