PURPOSE: Diets rich in nitrates have the potential to prevent oral diseases such as caries or periodontitis. The reduced forms nitrite and nitric oxide have an antibacterial effect against cariogenic bacteria. The effect on bacterial acid production in saliva and oral biofilm is yet unknown. This study investigated the influence of consuming naturally nitrate-rich beetroot juice on bacterial lactate production in saliva and on the pH value of saliva and oral biofilm.

MATERIALS AND METHODS: In addition to their usual diet, a study group of eight subjects consumed 50 ml of beetroot juice daily for a fortnight. After a two-week break, they rinsed with 0.2% chlorhexidine (CHX) for 14 days as a positive control. Bacterial lactate production was induced by rinsing with 50 ml apple juice and measured at different time points during the study.

RESULTS: After two weeks of daily beetroot-juice consumption, an accumulation of nitrate and nitrite was measured in the saliva. No influence on the bacterial lactate production in saliva or the saliva and plaque pH was found.

CONCLUSION: Commercially available beetroot juice showed no modulating effects on intraoral bacterial acid production, suggesting no caries-preventive properties under the tested conditions.