Examination of the Distribution of Nitrate Reducing Bacteria in the Human Oral Cavity

Dietary nitrate have been shown to have health benefits including lowering blood pressure (Hobbs et al, 2012), improving endothelial function and inhibiting platelet aggregation in healthy humans (Lidder \& Webb, 2013). The main sources of dietary nitrate in the human diet are vegetables such as beetroot. Nitrates are converted to nitrites then nitric oxide (NO), following their reduction by commensal oral bacteria and those residing in the gastrointestinal tract (Hord, Tang, \& Bryan, 2009; Lidder \& Webb, 2013). A recent study has shown following elimination of oral bacteria by the use of a chlorhexidine based antiseptic mouthwash, the conversion of nitrate to nitrite is prevented and this is accompanied by a statistically significant increase in blood pressure in normotensive subjects (Kapil et al., 2013). To date, very few studies have investigated the potential role of these oral bacteria in control of blood pressure and if there are any inter and intra-individual differences in bacterial composition.