DOES SELENIUM-ENRICHED FLOUR INCREASE PLASMA SELENIUM LEVELS? PLAN FOR A RANDOMISED CONTROLLED TRIAL

Introduction: Selenium (Se) is essential to humans, with several beneficial effects including anti-inflammatory and anti-oxidant properties. Higher Se status has been associated with better cognitive outcomes, while lower levels have been associated with higher mortality. Se intake has declined in UK and we know British wheat is deficient in Se. A strong negative association exists between plasma Se levels and the Frailty Index. Furthermore, a strong positive association has been shown between plasma Se and important commensal bacteria, even co-varying for frailty. A promising mechanism by which Se may impact health is through modulation of gut microbiome. Work in animal models has shown dietary Se levels affect the composition of our gut microbiome and vice versa. We propose a feeding trial to investigate health benefits and gut microbiome changes of selenium enriched flour in older adults with low baseline levels. Methods: 140 subjects will be recruited from the TwinsUK cohort, of which extensive baseline data is available. Approximately 970 volunteers are known to be deficient or deplete in Se. The design is a double blind randomised controlled trial, with volunteers replacing their breakfast carbohydrate with a rusk, either placebo or fortified with Se, over a 6 month period. Clinical and biochemical measures will be taken at 0, 6, months, with monthly contact during the study. Gut microbiota composition will be measured, along-side a battery of physical and cognitive assays. Conclusion: This project is a new collaboration between agricultural & medical scientists to understand how crop-based food can have positive health benefits. The work could lead to a substantial increase in our understanding of micronutrients, the gut microbiome and human health, which could have significant implications for UK agriculture going forward.