Nitrate-reducing Activity of Human Saliva

Abstract

We examined by statistical analysis the possible role of indigenous oral bacteria in nitrite formation in human saliva.In 13 volunteers' saliva, a relatively high positive correlation was observed between the nitrate-reducing activity of the saliva and the number of nitrate-reducing bacteria. However, there was no significant correlation between the nitrate-reducing activity of saliva and the concentration of salivary nitrite.The geometric mean rates (95% confidence limits of the mean) of nitrate reduction and of nitrite production of the saliva in vitro were only 0.94 (0.48-1.85)μg/ml/min and 0.37 (0.20-0.67)μg/ml/min, respectively. The estimated nitrate-reducing activity of indigenous oral bacteria in saliva thus does not support the hypothesis that the nitratereducing bacteria play an essential role in the formation of nitrite in the mouth.