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The role of dietary nitrate and the oral microbiome on blood pressure and vascular tone

Published online by Cambridge University Press:  07 December 2020

H. S. Alzahrani
Affiliation:
Hugh Sinclair Unit of Human Nutrition, Department of Food and Nutritional Sciences, University of Reading, Reading RG6 6DZ, UK Department of Food Science and Nutrition, King Saud University, PO Box 2454, Riyadh 11451, Saudi Arabia
K. G. Jackson
Affiliation:
Hugh Sinclair Unit of Human Nutrition, Department of Food and Nutritional Sciences, University of Reading, Reading RG6 6DZ, UK
D. A. Hobbs
Affiliation:
Hugh Sinclair Unit of Human Nutrition, Department of Food and Nutritional Sciences, University of Reading, Reading RG6 6DZ, UK
J. A. Lovegrove*
Affiliation:
Hugh Sinclair Unit of Human Nutrition, Department of Food and Nutritional Sciences, University of Reading, Reading RG6 6DZ, UK
*
*Corresponding author: Professor J. A. Lovegrove, fax +44 118 3787708, email j.a.lovegrove@reading.ac.uk

Abstract

There is increasing evidence for the health benefits of dietary nitrates including lowering blood pressure and enhancing cardiovascular health. Although commensal oral bacteria play an important role in converting dietary nitrate to nitrite, very little is known about the potential role of these bacteria in blood pressure regulation and maintenance of vascular tone. The main purpose of this review is to present the current evidence on the involvement of the oral microbiome in mediating the beneficial effects of dietary nitrate on vascular function and to identify sources of inter-individual differences in bacterial composition. A systematic approach was used to identify the relevant articles published on PubMed and Web of Science in English from January 1950 until September 2019 examining the effects of dietary nitrate on oral microbiome composition and association with blood pressure and vascular tone. To date, only a limited number of studies have been conducted, with nine in human subjects and three in animals focusing mainly on blood pressure. In general, elimination of oral bacteria with use of a chlorhexidine-based antiseptic mouthwash reduced the conversion of nitrate to nitrite and was accompanied in some studies by an increase in blood pressure in normotensive subjects. In conclusion, our findings suggest that oral bacteria may play an important role in mediating the beneficial effects of nitrate-rich foods on blood pressure. Further human intervention studies assessing the potential effects of dietary nitrate on oral bacteria composition and relationship to real-time measures of vascular function are needed, particularly in individuals with hypertension and those at risk of developing CVD.

Type
Review Article
Copyright
© The Author(s), 2020. Published by Cambridge University Press on behalf of The Nutrition Society

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