The purpose of this study is to determine the effects of the two doses of Jarro-Dophilus EPS® probiotic supplements on fecal lactobacillus and bifidobacteria numbers, transit survival of administered probiotic strains, fecal microbiota, gastrointestinal function and general wellbeing in healthy human adults.

Participants will be screened using the International Physical Activity Questionnaire (questions regarding physical activity, including intensity, duration and frequency) and inclusion/exclusion criteria. Participants will be scheduled to begin a 7-day baseline period, during which participants will complete daily questionnaires of bowel movement frequency, gastrointestinal symptoms and wellness. On or about day 8, height and weight will be determined. Participants will then be randomized to one of the following groups:

Group 1: Jarro-Dophilus EPS® (5 billion CFU/capsule), Group 2: Jarro-Dophilus EPS® Higher Potency (25 billion CFU/capsule), Group 3: Placebo capsule

Study participants will continue to complete the daily online questionnaire throughout the 28 days of treatment and for 7 days post treatment. Participants will also be asked to complete a weekly questionnaire on gastrointestinal symptoms (Gastrointestinal Symptom Rating Scale) throughout the entire study. In addition, participants in each group will be asked to collect one stool sample at baseline, one stool sample during week 4 of treatment and an additional sample during the washout period. Stool samples will be analyzed and quantified for the probiotic bacteria and changes in the microbiota.

Participants will be asked to return any unconsumed supplements at the end of the treatment period. Additionally, the participants will be weighed after the treatment period and the washout period.

Inclusion Criteria:

To participate in the study you must

• be between18-50 years of age
• be willing to have your height and weight measured and provide demographic information
• be willing to consume a probiotic or placebo capsule daily for 4 weeks
• be willing to provide 3 stool samples during the study
• be willing to complete a daily questionnaires regarding general and gastrointestinal wellness and the Gastrointestinal Symptom Rating Scale weekly throughout the entire 6-wk study
• have daily access to a computer with Internet access for the entire 6-wk study
• be willing and able to provide a valid social security for study payment purposes
• be willing and able to provide a valid social security for study payment purposes
• be willing to complete the International Physical Activity Questionnaire (asks you to report physical activity including intensity, duration and frequency)

Exclusion Criteria:

To participate in the study you must NOT

• be currently taking medications for constipation or diarrhea
• have previously or are you currently being treated for any diseases or illnesses such as gastrointestinal disease (gastric ulcers, Crohn's, Celiac, ulcerative colitis, etc.), other chronic diseases (diabetes, kidney disease, etc.) or immune-compromising diseases or conditions (HIV, AIDS, autoimmune, hepatitis, cancer, transplant patient etc.)
• have any known allergy to milk, milk protein, soy, gluten or have gluten sensitivity
• have taken antibiotics within the past 4 weeks prior to randomization
• be currently taking a probiotic supplement and are unwilling to discontinue it a minimum of 2 weeks prior to the study start
• be a current smoker.