The purpose of this study is to determine the effect of probiotic supplemented yogurt in reducing colonic transit time (CTT) in females between the ages of 18-65 years old. Two yogurts will be administered, one containing a specific strain of probiotic in the Bifidobacterium genus and the other without the probiotic supplement. It is hypothesized that subjects receiving the probiotic supplemented yogurt will experience reduced CTT and improved gastrointestinal comfort and quality of life compared to those receiving the non-probiotic supplemented yogurt.