Polyphenol-rich Haskap berries (Haskap) have untapped therapeutic potential to improve human health, and agricultural producers in northern U.S. states are poised to increase production if consumer demand increases. A critical knowledge gap is that little is known about the interactions between gut microbes and Haskap polyphenols to produce bioactive metabolites linked to downstream health impacts. Additionally, little is known about which Haskap varieties and harvest timing yield the greatest bioactive potential. This study aims to address these gaps by investigating the interaction of bioactive components in Haskap with gut microbiota and the resultant gut and serum metabolites, inflammation, and metabolic health, and then couple this with analysis of berries from different Haskap varieties and harvest times.

The long-term goal of this project is to form a partnership linking the health impacts of Haskap varieties and management practices that maximize health-promoting compounds to benefit both consumers and producers. Specific objectives of this study are to determine 1) the impact of Haskap on the gut microbiome and metabolome, 2) how gut microbiome composition and production of bioactive metabolites from Haskap impacts health and inflammation biomarkers, and 3) which Haskap varieties and growing practices increase production of health-promoting compounds.

To accomplish this, a four-armed, randomized, triple-blind, placebo controlled clinical trial of Haskap versus placebo for two separate groups with distinctly low and high metabolic syndrome status will be completed. Participants will be assessed for health biometrics, fat oxidation, gut microbiome composition, inflammation, and both the gut and serum metabolome before and after 8 weeks of intervention. Haskap fruit from twenty varieties will primarily come from the randomized block design field trial and fruit will be harvested at four stages of fruit maturity, then analyzed for polyphenol content. This part of the study will be replicated over three growing seasons.

Inclusion Criteria for Metabolically Healthy Group:

All of the following:

• Waist circumference: men ≤ 40, women ≤ 35 inches
• Systolic blood pressure: ≤ 130 mmHg
• Diastolic blood pressure: ≤ 85 mmHg
• Fasting glucose: ≤ 100 mg·dl-1
• Fasting triglycerides: ≤ 150 mg·dl-1
• HDL: men > 40, women > 50 mg·dl-1

Inclusion Criteria for Metabolically Unhealthy Group:

Required:

- Waist circumference: men ≥ 40, women ≥ 35 inches

AND ≥ 1 of the following:

• Systolic blood pressure: > 130 mmHg
• Diastolic blood pressure: > 85 mmHg
• Fasting glucose: > 100 mg·dl-1
• Fasting triglycerides: > 150 mg·dl-1
• HDL: men ≤ 40, women ≤ 50 mg·dl-1

Exclusion Criteria:

• BMI <18 or > 40 kg/m^2
• potential allergy to Haskap or placebo ingredients
• use of anti-inflammatory, lipid lowering, glucose lowering, blood pressure, or any other medications that may interfere with study measures
• pregnant or lactating woman
• diagnosis with type 1 or type 2 diabetes or any other condition that may interfere with study measures
• smoke cigarettes
• have taken antibiotics in the past 90 days
• take supplements including pre/probiotics or "superfoods" within 30 days of starting the study
• are planning on starting a weight loss or exercise regiment change
• follow a specific diet such as low carbohydrate, vegan, and vegetarian
• consume over 5 servings of fruit/vegetables per day
• are unwilling to reduce caffeine intake to one 8 oz serving per day for the durations of the study

Placebo and haskap interventions were designed to be comparable in taste and appearance.