Inside the Mouths of Vapers

Electronic cigarette use—also called vaping—has been on the rise. Thought to produce fewer toxic compounds than conventional cigarettes, e-cigarettes can still contain many harmful substances, including nicotine and heavy metals like lead.

Smoking conventional cigarettes is a known risk factor for the development of gum disease, or periodontitis. Part of this risk is driven by changes in the bacterial communities that normally live in the mouth, called the oral microbiome. Do e-cigarettes induce similar changes?

A team from New York University examined 84 volunteers over a 6-month period: 27 people who smoked conventional cigarettes, 28 who only used e-cigarettes and 29 nonsmokers. All participants had at least mild gum disease at the start of the study and none of the volunteers had a dental cleaning during the study period.

The team compared the types of bacteria found where the gums meet the teeth at the outset and after 6 months, as well as markers of inflammation and immune cell activity. Results of the NIDCR-funded study appeared in mBio.

The number of unique bacterial species—a measure called alpha diversity—living in and around the gums increased for all participants during the study. This can be a sign of worsening gum disease. 

But the specific types of microbes found in the oral microbiomes differed so substantially between the 3 groups that a machine-learning program could predict the people in each group with 74 percent accuracy.

However, the program was least accurate at picking out e-cigarette users. The patterns of their oral microbes shared characteristics with both smokers and nonsmokers, with slightly more similarities to smokers. 

Unique traits among e-cigarette users included enrichment with Fusobacterium and Bacteroidales species, both of which are linked with gum disease. Also, several markers of inflammation and immune response were higher in smokers and e-cigarette users than in nonsmokers.—adapted from NIH Research Matters