Characterization of Wild Blueberry Polyphenols Bioavailability and Kinetic Profile Over 24-hour Period

This study is a randomized, single blinded, 2-arm, within-subjects, placebo-controlled design utilizing a multiple sampling, repeated measures paradigm to characterize the bioavailability and kinetic profile of wild blueberry polyphenols.

A planned sample size of 12 will be enrolled into the study. This study will require one initial screening visit, one pre-study visit, and 2 study visits. This study will take approximately 3-4 weeks per subject to complete.

The initial screening visit will provide subject with the informed consent document and determine subject eligibility through anthropometric measurements, vital signs, fasting blood glucose test (finger prick), and completion of a survey relate to general eating, health, and exercise habits.

If willing and eligible to participate, a 3-day food record (2 weekdays and 1 weekend day) will be instructed at the Screening Visit and collected at the Pre-study visit to assess subjects' baseline dietary intake pattern. Subjects will be instructed to follow a strictly limited polyphenolic diet for 7 days prior to the study and throughout their participation time, while maintaining their usual diet pattern and physical activity, with counseling by staff investigator and/or Registered Dietitian. A dinner meal will be provided the day before the study visit to control the second meal effect from the food and beverage intake of the night before the study visit.

Subject will arrive at the center in a fasted state for at least 10 hours, well hydrated and rested. Each study visit will require blood draws throughout the visit. After evaluation of subject's health status (via anthropometric, vital sign and blood glucose measurements and in-person interview), a registered nurse will place a catheter in subject's arm for the purpose of multiple blood sample collections and take the initial blood draw in the fasting state. Subjects will be randomized to receive a placebo or wild blueberry beverage treatment based on randomized treatment sequences at 2 study visits along with 3 standard meals (breakfast, lunch and dinner). The sequences of receiving the beverage treatments at each visit will be randomly assigned to one of two of following sequences: placebo-wild blueberry or wild blueberry-placebo.

Each study visit will involve with blood samples collection at time points 0 (fasting), 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 24 hour (h) for assessment of change in plasma metabolites of wild blueberry polyphenols and influence of metabolic and inflammation markers. Also, urine samples will be collected prior to the study treatment as a baseline and all voids over 6 time periods, 0 to 2 h, 2 to 4 h, 4 to 6 h, 6 to 8 h, 8 to 10h and 10 to 24 h during each study visit to assess wild blueberry polyphenolic metabolites.