E-Cigarette Aerosol Adversely Affects Oral Microbiome

By Will Boggs MD

March 03, 2020

NEW YORK (Reuters Health) - Electronic cigarette aerosol alters the oral microbiome in a way that increases the risk of infection and inflammation, researchers report.

"E-cigarette vapor or aerosol may enhance infection and increase the abundance of opportunistic pathogens," Dr. Deepak Saxena of New York University College of Dentistry, in New York City, told Reuters Health by email. "The best practice is not to vape or smoke at all."

Previous studies have shown that liquids contained in e-cigarette vaping delivery systems can induce inflammatory responses, alter innate immune defenses, and impair pulmonary bacterial and viral clearance.

Dr. Saxena and colleagues assessed the influence of smoking on microbial profiles in their study of 39 never smokers, 40 e-cigarette users, and 40 regular cigarette smokers.

The severity of periodontal disease or infection was highest among cigarette smokers (72.5%), followed by e-cigarette users (42.5%) and non-smokers (28.2%).

The salivary microbiome differed significantly among the groups. The e-cigarette users had higher levels of Proteobacteria and both the cigarette smokers and e-cigarette users had higher levels of Actinobacteria, compared with never smokers.

Cigarette smokers also showed enrichment of Firmicutes and depletion of Fusobacteria, compared with e-cigarette users and never smokers, the researchers report in iScience.

In cell-culture studies, levels of the cytokines IL-1beta, TNF-alpha, IFN-gamma, IL-6, and IL-8 were increased in e-cigarette aerosol-exposed cells (versus air-exposed cells) co-infected with Porphyromonas gingivalis or Fusobacterium nucleatum, major perpetrators of periodontal destruction.

E-cigarette aerosol contact of cell cultures was also associated with 65% higher rates of P. gingivalis infection and 16% higher rates of F. nucleatum infection.

"The presented data suggest that vaping e-cigarettes causes oral environmental shifts and highly influences the colonization of complex heterogeneous microbial biofilms," the authors conclude. "More elaborate studies would help in identifying the detrimental effects of e-cigarette aerosols and its toxic components, albeit taking into consideration other confounding factors such as vaping behavior and the dual use of e-cigarettes and conventional cigarettes."

"E-cigarettes are not safe devices as promoted by companies," Dr. Saxena said. "They may be not as harmful as combustible cigarettes, but they are not safe."

Dr. Purnima Kumar from The Ohio State University, in Columbus, who has just published a review of e-cigarettes and the dental patient (https://bit.ly/2VwpNEm), told Reuters Health by email, "Dysbiotic microbiomes underlie the etiology of caries and periodontal diseases, and this study demonstrates an important mechanism by which we might see a rise in oral diseases in the future."

She also noted that "oral diseases contribute to the severity and progression of several systemic diseases, like rheumatoid arthritis, diabetes, cardiovascular diseases, and Alzheimer's."

"Hence, this study has important implications not only for dental health professionals, but also physicians," said Dr. Kumar, who was not involved in the new work. "E-cigarettes might provide an option for smoking cessation, but for individuals who have never smoked before, this study will serve as an important reminder that the risks of this behavior far outweigh the benefits."

SOURCE: https://bit.ly/2VnYgVI iScience, online February 26, 2020.