Background Aronia melanocarpa is a rich source of (poly)phenols. Previous research has demonstrated that these berries may provide cardiovascular health benefits in high-risk populations. However, very few studies have investigated the effects of daily consumption of dietary achievable amounts of the berries in healthy subjects. Objectives The aim of this study was to investigate the effects of aronia berries on vascular function and gut microbiota composition in a healthy population. Methods A double-blind, placebo-controlled, parallel designed study was conducted in 66 healthy men randomly allocated to consume a (poly)phenol-rich extract (116 mg, 75 g berries), a whole fruit powder (12 mg, 10 g berries), or placebo (maltodextrin) for 12 wk. Flow-mediated dilation (FMD), arterial stiffness, blood pressure, heart rate, and serum biochemistry were assessed. Plasma (poly)phenol metabolites were analyzed by LC-MS. Gut microbiota composition was determined via 16S rRNA sequencing in stool samples. Results Consumption of aronia whole fruit and extract powder for 12 wk led to a significant increase in FMD over control of 0.9% ± 0.4% (95% CI: 0.13%, 1.72%) and 1.2% ± 0.4% (95% CI: 0.36%, 1.97%), respectively. Acute improvements in FMD were also observed 2 h after consumption of aronia extract on day 1 (1.1% ± 0.3%, P = 0.003) and 12 wk later (1.5% ± 0.4%, P = 0.0001). Circulating plasma phenolic metabolites increased upon consumption of the aronia treatments. Although no changes were found in gut microbiota diversity, consumption of aronia extract increased the growth of Anaerostipes (+10.6%, P = 0.01), whereas aronia whole fruit showed significant increases in Bacteroides (+193%, P = 0.01). Correlation analysis identified significant associations between changes in FMD, aronia-derived phenolic metabolites, and specific gut microbial genera. Conclusions In healthy men, consumption of aronia berry (poly)phenols improved endothelial function and modulated gut microbiota composition, indicating that regular aronia consumption has the potential to maintain cardiovascular health in individuals at low risk of cardiovascular disease. This trial was registered at CLINICALTRIALs.gov as NCT03041961.

Nutritional epidemiological studies have frequently reported associations between higher (poly)phenol intake and a decrease in the risk or incidence of noncommunicable diseases. However, the assessment methods that have been used to quantify the intakes of these compounds in large-population samples are highly variable. This systematic review aims to characterize the methods used to assess dietary (poly)phenol intake in observational studies, report the validation status of the methods, and give recommendations on method selection and data reporting. Three databases were searched for publications that have used dietary assessment methods to measure (poly)phenol intake and 549 eligible full texts were identified. Food-frequency questionnaires were found to be the most commonly used tool to assess dietary (poly)phenol intake (73%). Published data from peer-reviewed journals were the major source of (poly)phenol content data (25%). An increasing number of studies used open-access databases such as Phenol-Explorer and USDA databases on flavonoid content since their inception, which accounted for 11% and 23% of the data sources, respectively. Only 16% of the studies reported a method that had been validated for measuring the target (poly)phenols. For future research we recommend: 1) selecting a validated dietary assessment tool according to the target compounds and target period of measurement; 2) applying and combining comprehensive (poly)phenol content databases such as USDA and Phenol-Explorer; 3) detailing the methods used to assess (poly)phenol intake, including dietary assessment method, (poly)phenol content data source; 4) follow the Strengthening the Reporting of Observational Studies in Epidemiology—Nutritional Epidemiology (STROBE-nut) framework; and 5) complementing dietary intake assessment based on questionnaires with measurement of (poly)phenols in biofluids using appropriate and validated analytical methods.

Background: Polyphenol consumption is implicated in gut microbiome composition and improved metabolic outcomes, but it is unclear whether the effect is independent of dietary fiber. Methods: We investigated the links between (poly)phenol intake, gut microbiome composition (16s RNA) and obesity independently of fiber intake in UK women (n = 1810) and in a small group of UK men (n = 64). Results: (Poly)phenol intakes correlated with microbiome alpha diversity (Shannon Index) after adjusting for confounders and fiber intake. Moreover, flavonoid intake was significantly correlated with the abundance of Veillonella, (a genus known to improve physical performance), and stilbene intake with that of butyrate-producing bacteria (Lachnospira and Faecalibacterium). Stilbene and flavonoid intake also correlated with lower odds of prevalent obesity (Stilbenes: Odds Ratio (95% Confidence Interval) (OR(95%CI)) = 0.80 (0.73, 0.87), p = 4.90 × 10−7; Flavonoids: OR(95%CI) = 0.77 (0.65, 0.91), p = 0.002). Formal mediation analyses revealed that gut microbiome mediates ~11% of the total effect of flavonoid and stilbene intake on prevalent obesity. Conclusions: Our findings highlight the importance of (poly)phenol consumption for optimal human health.

Background: Although widely used, there is limited understanding on the suitability of different dietary assessment tools to estimate (poly)phenol intake. This study aims to compare the agreement between a food...

Wholegrain oats contain a variety of phenolic compounds thought to help maintain healthy vascular function, through the maintenance of local levels of the vasodilator nitric oxide (NO). Thus, the full molecular mechanisms involved are not yet clear. With this work we aim to understand the possible cellular mechanisms by which avenanthramides and ferulic acid derivatives, present in oats, may help maintain a healthy vascular function through the modulation of the NO pathway. Primary Human Umbilical Vein Endothelial Cells (HUVEC) were exposed to ferulic acid, isoferulic acid, hydroferulic acid, ferulic acid 4-O-glucuronide, isoferulic acid 3-O-sulfate, dihydroferulic acid 4-O-glucuronide, avenanthramide A, avenanthramide B and avenanthramide C (1 μM) or vehicle (methanol) for 24 h. Apocynin and Nω-Nitro-L-arginine (L-NNA) were additionally included as controls. NO and cyclic GMP (cGMP) levels, superoxide production and the activation of the Akt1/eNOS pathway were assessed. The statistical analysis was performed using one-way ANOVA followed by a Tukey post-hoc t-test. Apocynin and all phenolic compounds increased NO levels in HUVEC cells (increased DAF2-DA fluorescence and cGMP), and significantly reduced superoxide levels. Protein expression results highlighted an increase in the Akt1 activation state, and increased eNOS expression. Overall, our results indicated that the glucuronide metabolites do not enhance NO production through the Akt1/eNOS pathway, thus all compounds tested are able to reduce NO degradation through reduced superoxide formation.