Nitrite and Oral Lactobacillus: A Systematic Review of Antibacterial Effects and Clinical Associations
Abraham Stephen Joshua1, Dimas Prasetianto Wicaksono2*, Ardianti Maartrina Dewi2
Abstract
Nitrite has been proposed as an endogenous oral antimicrobial factor, but its relationship with caries-associated Lactobacillus remains unclear. This systematic review evaluated the antibacterial effects of nitrite on oral Lactobacillus and associations between salivary nitrite-related measures and bacterial levels. PubMed, Web of Science, and Scopus were searched through 5 August 2026, supplemented by citation searching and exploratory semantic search. Eligible studies included in vitro experiments and cross-sectional studies reporting Lactobacillus-specific outcomes. Risk of bias was assessed using QUIN and JBI checklists. Findings were synthesized narratively because of methodological heterogeneity. Five studies were included: three in vitro experiments and two cross-sectional studies. All experimental studies reported inhibition of Lactobacillus, with two demonstrating greater inhibition at lower pH and higher nitrite concentrations. One disk-diffusion study reported concentration-dependent inhibition by potassium nitrite and greater inhibition when combined with fluoride. Clinical findings differed: one study reported an adjusted inverse association between salivary nitrite and Lactobacillus levels, whereas the other found no significant difference in bacterial counts between comparison groups. Experimental studies had moderate risk of bias; observational studies had moderate and high risk, respectively. Limitations included a small, heterogeneous evidence base and single-reviewer screening and extraction. Nitrite inhibits oral Lactobacillus under controlled experimental conditions, particularly when acidified, but clinical evidence does not establish causality or effectiveness for caries prevention. Prospective studies and multispecies biofilm models are needed.
Keywords
Nitrite; Lactobacillus; dental caries; oral microbiome; antibacterial activity; systematic review
Cite This Article
Joshua, A. S., Wicaksono, D. P., Dewi, A. M. (2026). Nitrite and Oral Lactobacillus: A Systematic Review of Antibacterial Effects and Clinical Associations. International Journal of Scientific Advances (IJSCIA), Volume 7| Issue 6: Nov – Dec 2026, Pages 886-895. URL: https://www.ijscia.com/wp-content/uploads/2026/11/Volume7-Issue6-Nov-Dec-No.1110-886-895.pdf
Volume 7 | Issue 6: Nov – Dec 2026
