B. Lactis B94 Effects of Gastrointestinal Function

The aim of this study is to determine the effect of daily consumption of Bifidobacterium animalis ssp lactis B94 (B. lactis B94) on stool frequency, gastrointestinal (GI) transit time, and gastrointestinal symptoms in adults with Prader-Willi syndrome. Participants (18-75 years old, n=36) will be recruited and enrolled in a 20-week randomized, placebo-controlled, crossover study. Study participants will be randomized to B. lactis B94 or placebo each for a 4-week period, preceded by a 4-week baseline and followed by 4-week washouts. Participants will complete daily questionnaires about stool frequency and stool form (transit). Dietary intake will also be assessed. A total of 5 stools (one in each period) will be collected for exploratory microbiota analysis. It is hypothesized that the B. lactis B94 will increase stool frequency, decrease the percentage of slow transit stools, and improve GI symptoms