ORCID
- Raul Bescos: 0000-0002-3939-4743
- Amazon Doble: 0000-0001-9658-030X
- Katie Muddiman: 0000-0002-0396-6893
- Robert Witton: 0000-0002-6424-4376
- Zoë LS Brookes: 0000-0002-8096-6256
Abstract
ObjectiveTo evaluate the impact of cigarette smoke on the activity and abundance of oral nitrate reducing bacteria (ONRB) in vivo and in vitro.Materials and MethodsAn observational study comprising of eleven cigarette smokers and thirty-one non-smokers. A saliva and nitrate-rinse sample were collected from each participant to analyse salivary biomarkers and the activity and abundance of ONRB in vivo. Additionally, the effect of cigarette smoke on the nitrate-reducing activity of four Rothia species was investigated in vitro.ResultsThe beta diversity of the oral microbiome was significantly different between smokers and non-smokers (P = 0.0063). Neisseria flavescens and Actinomyces oris were significantly higher in the saliva of smokers, however, Neisseria subflava, Neisseria oralis, Kingella denitrificans and Actinomyces georgiae were lower. Salivary nitrite levels were significantly lower in smokers (P = 0.034), along with a trend for decreased salivary pH (P = 0.058) and increased salivary thiocyanate (P = 0.018). In vitro exposure to cigarette smoke decreased the nitrate-reducing activity by Rothia species (P = 0.0046).ConclusionsSmoking decreased salivary nitrite levels and had a species dependent effect on ONRB abundance in vivo and inhibitory effect on the nitrate-reducing activity of Rothia species in vitro.Clinical significanceA ‘shift’ in the oral microbiome and inhibitory effect on nitrate reduction in smokers may contribute to an increased risk of oral and cardiovascular disease. Better understanding of this pathway may have the potential for development of interventions to decrease disease risk in this group.
DOI Link
Publication Date
2025-12-01
Publication Title
Journal of Dentistry
Volume
163
ISSN
0300-5712
Acceptance Date
2025-09-22
Deposit Date
2025-09-25
Funding
This research was funded by the Faculty of Health, University of Plymouth. The authors want to thank clinic manager, Aimee Matthews for initial clinic preparation. The authors also want to thank dental nurses, Ana Tarczanyn and Louise Carr, for aid with recruitment and data collection within PDSE. This study operated in conjunction with the University of Plymouth's Oral Microbiome Research Group (OMRG); equipment for anthropological measurements (blood pressure, BMI) was supplied within the OMRG group. This study also operated in conjunction with Peninsula Dental Social Enterprise for the use of clinic facilities and computer integrated R4 systems to securely record and store patient data.
Additional Links
Keywords
oral microbiome, nitrate, nitrite, nitric oxide, Smoking, Cardiovascular, Rothia
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Nicholas, T., Bescos, R., Doble, A., Muddiman, K., Kellett, P., Stephen, A., Toit, L., Witton, R., & Brookes, Z. (2025) 'A pilot study investigating the impact of cigarette smoking on oral nitrate-reducing bacteria within the oral microbiome', Journal of Dentistry, 163. Available at: 10.1016/j.jdent.2025.106127
