2017 ASHS Annual Conference

When it comes to capturing health-protective benefits from functional foods or superfruits, the concentration of bioactive phytochemicals in the plant or food is not nearly as important as the bioavailability of those phytochemical in the human body. There’s an enormous gap between recommended levels of fruits and vegetables for human health and the actual amounts that consumers purchase and eat, so, finding approaches that deliver more phytoactive compounds in every serving is essential. Using the blueberry and its wild relatives as a model for investigation, we have adapted novel strategies to determine absorption and bioavailability of polyphenolic phytochemicals in humans after ingestion. Vaccinium reticulatum (ohelo), a wild relative of cranberry and blueberry that is abundant at higher altitudes around volcanic regions of Hawai’i Volcanoes National Park, has provided an excellent model for investigating the metabolic fate, stability, absorption and bioavailability of anthocyanins, proanthocyanidins, and other polyphenolic compounds in Vaccinium fruits that are well known for their cardioprotective, neuroprotective, and anti-diabetic properties. A model of the human gastrointestinal tract (TIM-1) that mimicked the biological environment from the point of swallowing and ingestion through the duodenum, jejunum, and ileum (but not the colon) was used to monitor the stability and bioaccessibility of anthocyanins wild berryfruit. TIM-1 revealed that most anthocyanins were bioaccessible between the second and third hours after intake, and that delivery of the bioactives in a protein matrix protected their stability. Alternatively, biolabeled anthocyanins and other flavonoids generated in vitro from berry and grape cell cultures were administered to in vivo (rodent) models, allowing measurement and tracking of the absorption and transport of berry constituents and clearance through the urinary tract and colon. This strategy permitted us to track deposition of radiolabeled flavonoid metabolites into brain tissues. Finally, semi/untargeted metabolite profiling in human fluids (blood, urine, and feces) by LC-MS methods has provided our team with highly detailed information on metabolic signatures after consumption of wild berries. Each of these transformative strategies provide unprecedented markers of intake/exposure to active phytochemicals, and suggest methods for high throughput phenotyping to select fruits with exceptional bioavailability in humans.