The BacterioPHAGE for Gastrointestinal Health-2 study is designed to determine if a commercial bacteriophage product can increase the survival and efficacy of probiotic bacteria that will be concurrently administered. Bacteriophages may act as prebiotics, which are traditionally defined as indigestible dietary components that selectively enhance specific bacterial species in the intestines to confer a health benefit. In this study, the "prebiotic" is a unique combination of bacteriophages, or viruses that infect bacteria. These phages are generally regarded as safe for human consumption and are presumed to function by infecting pro-inflammatory E. coli strains in the gut. The removal of these strains alters the gut environment to allow growth of more favorable bacteria, and the lysis products of these E. coli may be assimilated by beneficial species to enhance their populations.The phage product, PreforPro, has shown to be effective in culture-based and animal studies, but its efficacy in increasing specific probiotic species has not been demonstrated in humans. The investigators have previously shown that PreforPro is both safe and tolerable in a human population and does not broadly disrupt the gut microbiota as would be seen with antibiotic treatment.

The commercial bacteriophage preparation,PreforPro, is often found as an ingredient in commercial probiotcs, so the goal of the current study is to determine if PreforPro consumption concurrent with probiotic usage improves probiotic survival and activity. A secondary goal of this study is to assess various physiologic parameters to determine whether consumption of PreforPro with a probiotic offers any health benefits beyond those of consuming a probiotic alone. The investigators will examine whether consumption of the PreforPro product increases detectable numbers of co-consumed probiotics and improves parameters in clinical outcomes related to glucose and lipid metabolism, cardiovascular function, inflammation of the intestines, or physical symptoms of gastrointestinal distress.

To accomplish these research goals, the investigators will be seeking 200 male and female volunteers between 18-65 years old with BMI scores of 22 to 34.9. Recruitment will be by referral from local practitioners, email recruitment, and through word-of-mouth. Eligibility will be determined at the Colorado State University Food and Nutrition Clinical Research lab by a screening questionnaire and interview/assessment by the clinical coordinator. After securing consent, eligibility will be confirmed by taking anthropometric measures and participants falling within the BMI range will randomly be assigned to 1 of 3 treatment groups: (1) PreforPro+Bifidobacterium probiotic, (2) Bifidobacterium probiotic alone, or (3) placebo. Participants will consume the provided capsules daily for a period of four (4) weeks. Participants will be asked to visit the clinic at Visit 1 (Day 0) to pick up their supply of capsules and undergo sample collections (blood and stool) and analysis procedures, including weight/height, blood pressure, endothelial function analysis, gastrointestinal symptom screening, and blood and stool sample collection. At the end of the 4 week treatment period, all analyses will be repeated. This means that participants will undergo screening (either in person or by phone) and make a total of two (2) clinic visits during the study (baseline, and final visit). Participants will additionally be asked to complete two 24 hour dietary recalls prior to each clinic visit and track bowel movements using the Bristol Stool Scale throughout the study treatment period. All blood samples will be collected at Colorado State University by trained personnel. Fecal sample collection will be performed by the study participant with collection materials provided.

Inclusion Criteria:

• healthy
• 18-65 years old
• BMI 20 to 34.9

Exclusion Criteria:

• individuals less than 18 years of age or greater than 65 years of age
• outside of the BMI range of 20-34.9
• antibiotic or probiotic/prebiotic supplements within two months of the start of treatment
• use of statins, metformin, NSAIDs, MAO inhibitors, and botanical supplements that target the GI tract or gut microbiota
• current diagnosis of cancer, liver or kidney disease, gastrointestinal diseases, and metabolic disorders
• pregnant and breastfeeding women
• unable to adhere to the study requirements

Treatment capsules are provided by Deerland Enzymes in coded packaging. Participants, investigators, and data assessors will not be provided the key to the codes. Once all data is entered and analyzed, the keys will be provided by Deerland.