Vaping and smoking: do they have the same impact on the microbiota?

According to an American study, contrary to smokers, electronic cigarette users have a similar bacterial profile to that of non-smokers, in the intestines, mouth and saliva.


Presented as an alternative to smoking, and especially as a means to stop smoking, e-cigarettes are increasingly popular. This is evidenced by the constant increase of the number of vapers, multiplied by three every year in the US. Mainly composed of propylene glycol, vegetable glycerin and nicotine, e-cigarettes claim to have a lower toxicity than regular cigarettes and their 4,000 chemical substances. But what is the impact of e-cigarettes on oral (mouth and saliva) and intestinal microbiota? To face this lack of scientific works on this subject, a team of American researchers conducted a study with 30 volunteers: 10 smokers, 10 vapers and 10 control subjects (who did not smoke tobacco nor use electronic cigarettes).

Tobacco and microbiota don’t mix

The intestinal flora of vapers and non-smokers was relatively similar. Nonetheless, compared to that of non-smokers, the intestinal microbiota of tobacco consumers had less diverse and abundant microorganisms. An increase in the levels of Prevotella and a decrease in Bacteroides were also observed. The analysis of samples from the mouth and saliva, two sites directly exposed to tobacco smoke or e-cigarette vapor, also revealed differences between tobacco smokers and non‑smokers, whose bacterial profiles are similar to those of vapers.

Using e-cigarettes has no impact on microbes

Only tobacco has a harmful effect on the microbiota composition, in particular in the intestines. E‑cigarettes have no significant impact on the microbiota, and in this respect, they can be a less dangerous alternative to regular cigarettes, according to the authors, although they believe investigations should be further pursued.



Stewart et al. Effects of tobacco smoke and electronic cigarette vapor exposure on the oral and gut microbiota in humans: a pilot study. PeerJ. 10.7717/peerj.4693