The Effects of Dietary Fiber on the Gut Microbiome and HDL Particles of Human Subjects

Open to people ages 18-45

• Healthy male and female adults 18-45 years old
• BMI: 23.0-32.0 kg/m2 ("overweight")
• Current diet includes low quantity of fiber, defined as less than approximately 15g/day, or equivalent to approximately 4 servings of fruit, vegetable, legume, or whole grain combined per day, and determined using diet recall.
• Willingness to consume prebiotic fiber drink daily for 4 weeks, and a placebo drink for 4 weeks, as well as a 4-week washout period with no intervention.
• Willingness to provide diet records, blood samples and stool samples (self-collected) biweekly for the duration of the study (7 total collections).
• Willingness to adhere to "diet control period" biweekly (eating the same, self-selected foods and abstaining from alcohol each day for 3 days prior to each stool collection/blood draw).
• General bowel movement frequency of at least once every three days and maximum of two times per day.

• A plan to or desire to lose weight
• Smoker
• Anemia and difficulty with blood draws
• Currently, within previous 6 weeks of the study, or during the study taken probiotic or prebiotic formulations (food products considered to have these properties in their natural or unadulterated forms are acceptable).
• Antibiotic use during the study or within 6 months prior to study commencement.
• Medication: statins, blood pressure medications, other prescription medications
• Pregnant, planning to be pregnant or breast feeding at any point during the study or study enrollment.
• Start or change in use of hormonal birth control in the last 6 months or plans to change or start use of hormonal birth control during the study period
• Allergies to any prebiotic or placebo ingredients - Prebiotic ingredients: Resistant Tapioca Starch, Fructooligosaccharide, Sugarcane Fiber, Agave Inulin, Gum Arabic,

Xanthan Gum, Apple Powder, Raspberry Powder, Blueberry Powder / Placebo Blend: Rice Flour, Xanthan Gum, Grape Powder, Plum Powder

• Illness (flu/cold in the last two weeks)
• Documented chronic diseases including diabetes, thyroid disease, metabolic syndrome, hypertension, cancer, or previous cardiovascular events
• Irritable bowel syndrome, celiac disease, or any inflammatory bowel disease (including Crohn's Disease, and/or Ulcerative colitis)
• Any immunosuppression symptoms at any point during the study or study enrollment
• Consumption of >1 alcoholic drink/day or frequent binge drinking (>3 alcoholic drinks in one episode) > 1 day per month
• Plans to change or recent significant changes in lifestyle (e.g. diet or exercise routine, major travel, etc)
• Recent weight fluctuations (greater than 10% in the last six months)
• Regular use of over-the-counter pain medications (>1/week)
• Taking prescription lipid medications (e.g. statins) or other supplements known to alter lipoprotein metabolism such as isoflavones
• Recent medical procedure such as surgery within the last 6 months
• Any changes in the above during the course of the study