Background: Increasing evidence from both epidemiological studies and randomised-controlled trials (RCT’s) suggests that (poly)phenol-rich foods, such as blueberries, can improve vascular function, reducing the risk of developing cardiovascular diseases. In addition, (poly)phenols are thought to improve beneficial gut bacteria and improve gut microbial diversity. There is limited evidence in older populations, already at increased disease risk, and whether blueberry (poly)phenols can improve such health outcomes. 
In this study, we aim to investigate whether daily wild blueberry supplementation can lead to changes in vascular function (measured as flow-mediated dilation, FMD), cerebral blood flow (CBF) and improve the gut microbiome in a cohort of healthy elderly individuals. 
Methods: A parallel, double blind, placebo controlled RCT was conducted in 61 healthy individuals, aged 65-80. The impact of wild blueberry (poly)phenols on FMD, active and resting CBF using transcranial doppler ultrasound, and 24 h blood pressure (BP) was assessed at baseline and 12-weeks following daily consumption of 26 g freeze-dried blueberry powder, containing 264 mg anthocyanins (equivalent to 178 g fresh wild blueberries), or a macronutrient and micronutrient matched control drink (0 mg anthocyanins). Faecal samples were collected to measure changes in the gut microbiome. Blood and 24 h urine samples were also collected to analyse (poly)phenol metabolites. Linear mixed model analysis was performed as the statistical method. 
Results: FMD improved by 0.86 % (f=32.8, p<0.001) in the blueberry group compared with the placebo group after 12-weeks daily consumption. Systolic 24 h ambulatory BP decreased by -3.59 mmHg (f=4.6, p=0.037) in the blueberry group compared to the placebo group. No other vascular outcome changed significantly following daily blueberry consumption. Results for the gut microbiome changes and with the plasma and urine (poly)phenol concentrations will be available at the time of this conference. 
Discussion: Daily consumption of wild blueberry (poly)phenols improves FMD and blood pressure in a healthy elderly population. This suggests that daily blueberry consumption can improve vascular function in an at-risk population. However, arterial stiffness and cerebral blood flow did not change. More research is needed to investigate whether blueberries can improve such outcomes in elderly individuals with pre-existing cardiovascular risk factors such as hypertension.

Effects of daily wild blueberry (poly)phenol consumption on vascular function in a healthy elderly population: the BluFlow study

The gastrointestinal tract is amongst the most densely populated ecosystems on earth, home to an abundant and diverse collection of microbial species, not just bacteria but also Archaea, viruses, fungi etc. Significant interest in this area has been sparked in recent years by an appreciation of the importance of the gut microbiota in the health of the host, and this has led to the microbiome of humans and animals being investigated in depth. Studies have drawn links between host nutrition, the gut microbiota and metabolic and immune functions, which in consequence affect physiology.



The first investigations of the structure of the microbiota were culture-based, however the introduction of sequencing technologies such as Sanger sequencing and subsequent development of 454 sequencing and metagenomics approaches have become the mainstay of microbiota studies. The creation of reference databases and analysis software has provided invaluable tools for assigning taxonomy to generated data. Great progress in characterising the structure of the microbiome recently has paved the way for ongoing and future studies on the functional interactions between the microbiota and the host. Studies on the function of the microbiota are critical in understanding the role of the microbiota in human homeostasis and disease pathogenesis.



The conference will be presenting the latest advancements in gut microbiome and health research. It will bring together experts who are driving technological advancements and striving to understand how nutrition impacts gut microbiome and the interactions between gut microbiome and health.



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Recordings of the conference will be available until 13 April 2021.