Researchers find that e-cigarette use disrupts the nasal microbiome

The nose plays more roles than just smelling and shaping our facial profiles. It also acts as a gatekeeper for the respiratory tract and can prevent bacteria and other pathogens from leaving the nasal cavity and settling in the lungs.

Like the microbiome in the gastrointestinal tract and skin, the precious balance of beneficial bacterial, fungal and viral colonies in the nose can be disrupted. This imbalance, called dysbiosis, can lead to an overgrowth of harmful bacteria and predispose people to respiratory diseases, such as chronic obstructive pulmonary disease and asthma.

Elise Hickman, Ph.D., a former student in the laboratory of inhalation toxicologist Ilona Jaspers, Ph.D., director of the UNC Center for Environmental Medicine, Asthma, and Lung Biology at the UNC School of Medicine, discovered that e-It cigarette and cigarette use can cause an imbalance in the nasal microbiome.

Their study, published in Nicotine and tobacco researchcould be important in understanding the immunological implications of vaping and smoking.

“We found that the composition of the nasal microbiome varies depending on gender, e-cigarette versus cigarette use, and how much of a nicotine biomarker is found in the blood,” says Hickman, who is now a postdoctoral researcher in the Department of Environmental Sciences and engineering at the UNC Gillings School of Public Health.

“Our findings warrant further investigation into why and how e-cigarette use disrupts the immune system in the nasal microbiome and causes imbalances in the respiratory microbiome.”

Previous research from the Jaspers lab showed that the use of e-cigarettes can influence the daily functioning of the immune system in the nose and make someone more susceptible to viral infections such as flu. Knowing that the respiratory microbiome supports respiratory immune defense, Hickman and Jaspers wanted to know whether dysbiosis in the nasal microbiome, which is often linked to lower respiratory diseases, could be caused by e-cigarette or cigarette use.

In collaboration with Matt Wolfgang, Ph.D., and Cristian Roca of the Marsico Lung Institute/UNC Cystic Fibrosis Center, Hickman and Jaspers collected and analyzed fluid samples from the nasal epithelium of 20 nonsmokers, 28 e-cigarette users, and 19 smokers . They then used genetic sequencing to identify the type and amount of bacteria in the nasal microbiome.

Researchers identified different bacteria, some harmful and others protective, depending on whether people used e-cigarettes, smoked regular cigarettes or neither. Staphylococcus aureus, a bacteria that can cause pneumonia and other life-threatening infections, was found in higher numbers in e-cigarette users and smokers than in non-smokers. Lactobacillus iners – a beneficial bacteria that can protect against respiratory diseases – was found more often in smokers than in non-smokers.

Surprisingly, researchers found that there were differences in the microbiomes of male and female e-cigarette users. Hickman and Jaspers also found that there were differences in nasal bacteria between people with high and low levels of cotinine, a metabolite and indicator of nicotine exposure.

“Taken together, our data have identified a unique, sex-dependent host immune dysfunction associated with e-cigarette use in the nasal mucosa,” said Jaspers, who is also a member of the UNC Lineberger Comprehensive Cancer Center and researches inhaled toxic substances and their effects on the respiratory mucosa. .

This research adds to the increasing number of studies showing the respiratory health effects associated with e-cigarette use. Given that there is mounting research showing that changes in the nasal microbiome may be linked to lung disease and health, dysbiosis in the balance of harmful and protective bacteria in the noses of e-cigarette users should be of concern.