Impact of Smoking on Oral Microbiome Dynamics

Smoking introduces a complex mixture of chemicals and particulates that disrupt the ecological balance of the oral microbiome. The oral cavity hosts distinct bacterial communities on teeth, mucosal surfaces and in saliva. Tobacco smoke reduces commensal diversity and promotes the overgrowth of opportunistic and pathogenic taxa, leading to a dysbiotic state. These shifts compromise periodontal health, impair immune responses and may contribute to systemic inflammation. Mechanistically, smoking alters oxygen levels, pH and nutrient availability, driving changes in colonisation patterns, interspecies interactions and metabolic pathways. Although some microbial disturbances partially reverse after cessation, long-term exposure establishes persistent community alterations. The interplay with factors such as oral hygiene, tooth loss and environmental co-exposures further shapes microbial dynamics, underscoring the need for integrated studies to inform targeted prevention and restoration strategies.

Research from Nature Portfolio

Longitudinal sampling of cigarette and smokeless tobacco users alongside non-users over four months revealed that tobacco consumption increases overall bacterial richness but skews community composition. Users exhibited higher proportions of Firmicutes and lower Proteobacteria, with opportunistic pathogens such as Porphyromonas endodontalis appearing more frequently. Although dominant genera remained stable, several species showed significant temporal shifts, illustrating the dynamic impact of tobacco on oral communities.

A foundational investigation in a Middle Eastern cohort compared cigarette, dokha and shisha use, finding that cigarette and dokha consumption significantly altered oral community structure, whereas shisha had minimal impact. Taxa linked to periodontal disease, including Actinobacillus and Porphyromonas, were enriched in cigarette smokers, indicating product-specific dysbiosis and potential oral disease risk.

Impact of Smoking on Oral Microbiome Dynamics publication trend

The graph below shows the total number of articles in impact of smoking on oral microbiome dynamics across all publications each year (not limited to Nature Index journals).

Technical terms

Alpha diversity: Measure of species richness and evenness within a single microbial sample.

Beta diversity: Comparison of community composition between samples, indicating similarity or dissimilarity.

Dysbiosis: Microbial imbalance marked by loss of beneficial taxa and proliferation of potentially harmful species.

Subgingival microflora: Bacterial communities residing below the gum line in periodontal pockets.

16S rRNA sequencing: Technique targeting the 16S ribosomal RNA gene for bacterial identification and quantification.

References

1. Oral microbiome dysbiosis among cigarette smokers and smokeless tobacco users compared to non-users. Scientific Reports (2024).
2. Types of tobacco consumption and the oral microbiome in the United Arab Emirates Healthy Future (UAEHFS) Pilot Study. Scientific Reports (2018).
3. Smoking, tooth loss and oral hygiene practices have significant and site-specific impacts on the microbiome of oral mucosal surfaces: a cross-sectional study. Journal of Oral Microbiology (2023).
4. Association of cigarette smoking with oral bacterial microbiota and cardiometabolic health in Chinese adults. BMC Microbiology (2023).
5. The impact of interactions between heavy metals and smoking exposures on the formation of oral microbial communities. Frontiers in Microbiology (2024).