Evaluating the Impact of an Aronia Berry Dietary Supplement on Vascular Endothelial Function and the Gut Microbiota in Healthy Middle-Aged/Older Adults: Study Protocol. (29th May 2020) - Vazquez, Allegra
Abstract: Objectives: Aging is the primary risk factor for cardiovascular disease (CVD) largely due to vascular endothelial dysfunction, an initiating step in the development of atherosclerosis. The gut microbiota has emerged as an important regulator of cardiovascular health. Aronia berries are rich in polyphenols such as anthocyanins, proanthocyanidins, and phenolic acids. These compounds, and metabolites resulting from gut microbial and phase II metabolism, have been shown to improve endothelial function. The primary objective of this study is to assess the dose-dependent efficacy of an aronia berry full spectrum dietary supplement to improve vascular endothelial function in middle-aged/older men and postmenopausal women. A secondary goal is to determine whether aronia full spectrum modulation of the gut microbiota is associated with improvements in vascular endothelial function. Methods: Healthy men and postmenopausal women (n = 28) aged 45–75 years are being recruited for this randomized, double-blind, placebo-controlled, crossover trial. In random order, participants take a placebo, 500 mg aronia full spectrum, or 1000 mg aronia full spectrum daily for a 6-week period. Each treatment period is separated by a 6-week washout period. The primary outcome is reactive hyperemia index (RHI), a validated measure of vascular endothelial function assessed using peripheral arterial tonometry. Secondary outcome measures include analysis of the gut microbiota in stool samples, hemodynamic parameters including blood pressure and augmentation index, arterial stiffness, and blood biomarkers of cardiovascular and metabolic health including blood lipids, hemoglobin a1c, oxidized LDL, and adhesion molecules. Other outcome measures will include plasma, fecal, and urine polyphenol metabolites. Gut microbial populations will be statistically compared with RHI. Results: To date, a total of 22 individuals (11 men/11 women) have been enrolled in the trial and randomized to their intervention order. Of these, 3 have completed the study, 1 was lost to follow-up, and 18 are currently enrolled. Conclusions: We hypothesize that this aronia berry dietary supplement will dose-dependently improve vascular endothelial function in healthy middle-aged/older adults, and that improvements will be linked to modulation of the gut microbiota. Funding Sources: Naturex.