The relationship between e-cigarette use and oral health remains a topic of active scientific debate. While some studies have suggested potential risks, the underlying evidence is often fragmented and difficult to interpret.
A new CoEHAR systematic review, published in the Journal of Clinical Periodontology, takes a closer look at one specific aspect: whether vaping is associated with changes in the oral microbiota — the complex community of microorganisms living in the mouth.
The review analyzed 12 human studies using advanced molecular techniques across different oral sites, including saliva, subgingival plaque, and oral mucosa.
Across the studies, e-cigarette users often showed differences in their oral microbiota compared with both never smokers and current smokers. However, these changes were not consistent.
No single “vaping-associated” bacterial profile emerged. Findings varied depending on:
- The sampling site (saliva, plaque, mucosa)
- The population studied
- The analytical methods used
This variability makes it difficult to identify a clear or reproducible microbiological signature linked to vaping.
What do these changes mean?
Importantly, changes in the oral microbiome do not necessarily translate into disease. Most of the studies included in the review were small and cross-sectional, meaning they captured a single point in time and cannot establish cause-and-effect relationships. In addition, many participants were former smokers or dual users, making it challenging to isolate the specific impact of vaping from past or ongoing smoking exposure.
As a result, while microbiome differences have been observed, their clinical significance remains uncertain.
The need for stronger evidence
The authors highlight the need for larger, well-designed longitudinal studies that follow individuals over time and better control for confounding factors such as previous smoking history. Only this type of research can clarify whether the observed microbiome changes are transient adaptations, neutral variations, or markers of potential long-term risk.
As emphasized by Prof. Riccardo Polosa, founder of CoEHAR and co-author of the study:
“Changes in the mouth microbiome can reflect many different things, but on their own they do not prove oral disease. So, it is premature to claim that vaping causes oral harm, even if some commentaries imply otherwise.”
Taken together, the review suggests that while vaping may be associated with shifts in oral bacterial communities, current evidence does not support definitive claims of oral harm.
About the article
La Rosa GRM, Samaranayake LP, Zaura E, Sun A, Fuochi V, Furneri PM, Kowalski J, Myszel K, Chapple I, Polosa R.
Impact of Electronic Cigarette Use on the Oral Microbiota: A Systematic Review.
Journal of Clinical Periodontology. 2026.
DOI: 10.1111/jcpe.70111
https://pubmed.ncbi.nlm.nih.gov/41856754/