The Effects of Chronic Nitrate Supplementation and the Use of Strong and Weak Antibacterial Agents on Plasma Nitrite Concentration and Exercise Blood Pressure

Abstract

Chlorhexidine-containing mouthwash (STRONG), which disturbs oral microflora, has been shown to diminish the rise in plasma nitrite concentration ([NO2-]) and attenuate the reduction in resting blood pressure (BP) typically seen after acute nitrate (NO3-) ingestion. We aimed to determine whether STRONG and weaker antiseptic agents attenuate the physiological effects of chronic NO3- supplementation using beetroot juice (BR). 12 healthy volunteers mouth-rinsed with STRONG, non-chlorhexidine mouthwash (WEAK) and deionised water (CON) 3 times a day, and ingested 70 mL BR (6.2 mmol NO3-), twice a day, for 6 days. BP (at rest and during 10 min of treadmill walking) and plasma and salivary [NO3-] and [NO2-] were measured prior to and on day 6 of supplementation. The change in salivary [NO3-] 4 h post final ingestion was higher (P<0.05) in STRONG (8.7±3.0 mM) compared to CON (6.3±0.9 mM) and WEAK (6.0±3.0 mM). In addition, the rise in plasma [NO2-] at 2 h was lower in STRONG compared with WEAK (by 89±112 nM) and CON (by 200±174 nM) and in WEAK compared with CON (all P<0.05). Changes in resting BP were not different between conditions (P>0.05). However, during treadmill walking, the increase in systolic and mean arterial BP was higher 4 h after the final nitrate bolus in STRONG compared with CON (P<0.05) but not WEAK. The results indicate that both strong and weak antibacterial agents suppress the rise in plasma [NO2-] observed following the consumption of a high NO3- diet and the former can influence the BP response during low-intensity exercise.

No effect of beetroot juice supplementation on exercise economy and performance in recreationally active females despite increased torque production

“…The use of antibacterial mouthwash and chewing gum was prohibited during the experimental trials, as there is evidence suggesting that these substances destroy the anaerobic bacteria in the mouth necessary for the conversion of to NO 2 − and NO (McDonagh et al. ). Furthermore, the subjects were instructed to avoid brushing their teeth for 2 h before and after the ingestion of the BRJ or placebo (PLA).…”

“…The use of antibacterial mouthwash and chewing gum was prohibited during the experimental trials, as there is evidence suggesting that these substances destroy the anaerobic bacteria in the mouth necessary for the conversion of NO À 3 to NO 2 À and NO (McDonagh et al 2015).…”

Enterosalivary nitrate metabolism and the microbiome: Intersection of microbial metabolism, nitric oxide and diet in cardiac and pulmonary vascular health

“…However, the answer remains unclear. Two studies have since shown increased blood pressures after chlorhexidine-containing mouthwash treatment in a population of hypertensive men on antihypertensive therapy[428] and during exercise in healthy volunteers[429], while a recent crossover study in healthy women showed no blood pressure effects with similar treatment[430]. Conversely, epidemiological studies consistently show that in the general population, good oral hygiene (specifically frequent tooth brushing and mouthwash use) protects against development of hypertension and CVD[431–433].…”

“…Conversely, epidemiological studies consistently show that in the general population, good oral hygiene (specifically frequent tooth brushing and mouthwash use) protects against development of hypertension and CVD[431–433]. Such incongruities may be in part explained by evidence suggesting that one’s choice in mouthwash (from the strongest bactericidal formulations with chlorhexidine, to weaker ones such as with triclosan or cetylpyridinium, to the widely available and weakest antiseptic formulations) greatly impacts the degree of bacterial nitrate reduction and blood pressure effects[99,429,434], and that brushing with even bactericidal toothpaste exerts little to no effect on bacterial nitrate reduction[434]. Clearly, further targeted studies will be needed to fully understand if regular antimicrobial mouthwash use truly impacts the risk for development of PH and its risk factors.…”

Effect of sodium nitrite on local control of contracting skeletal muscle microvascular oxygen pressure in healthy rats

“…These steps typically take hours to raise plasma [NO 2 Ϫ ] (60) and can be blocked by mouthwash-induced bactericide (41).…”