E-cigarette users and smokers had significantly higher amounts of Staphylococcus aureus in their respiratory microbiome than nonsmokers, and microbial diversity differed by sex, according to a new analysis. Researchers in a new study also found that Lactobacillus iners, usually seen as a protective species, was more prevalent in smokers than in nonsmokers, whereas less prevalent in e-cigarette users than in nonsmokers.
The respiratory microbiome is thought to help protect the lower respiratory tract from pathogens, but the specific effects of e-cigarettes on the respiratory or nasal microbiome have not been well studied, wrote Elise Hickman, PhD, of the Center for Environmental Medicine, Asthma and Lung Biology at The University of North Carolina at Chapel Hill, and colleagues.
“Identifying how e-cigarette use modifies the nasal microbiome is another step in understanding how vaping affects lung health,” said lead investigator Ilona Jaspers, PhD, in an interview.
In a study published in Nicotine & Tobacco Research, the investigators used 16S rRNA gene sequencing to examine the respiratory microbiomes of 57 healthy adults aged 18-50 years: 20 nonsmokers, 28 e-cigarette users, and 19 smokers. The researchers collected serum cotinine measurements as an indicator of nicotine exposure, and participants completed questionnaires as to their smoking habits.
Smokers reported an average of 12.68 cigarettes per day. The 13 e-cigarette users who reported puffs per day averaged 53.90 puffs per day, and the 16 who reported mL of liquid per day and e-liquid nicotine concentration averaged 3.60 mL of e-liquid and 19.43 mg/mL of nicotine in e-liquids.
Overall, the researchers found an increase in S aureus in smokers and e-cigarette users compared with nonsmokers. By contrast, L iners was more abundant in smokers than in nonsmokers but less abundant in e-cigarette users than in nonsmokers.
Notably, among e-cigarette users, the microbial beta diversity was significantly different between male and female participants, although this was not the case in cigarette smokers.
For example, Propionibacterium acnes was decreased in smokers and e-cigarette users compared with nonsmokers. However, men demonstrated an increase in Haemophilus parainfluenzae and P acnes and a decrease in S aureus compared with women.
The researchers also stratified smokers and e-cigarette users into groups based on cotinine (a nicotine metabolite) to examine the impact of nicotine on changes in the nasal microbiota. Among smokers, microbial diversity was significantly decreased in those with cotinine levels> 151 ng/mL vs those with cotinine levels ≤ 151 ng/mL. However, the opposite was true for the e-cigarette users (P <.05 for both were surprised by the clear sex differences in nasal microbiome jaspers told medscape medical news. we have previously shown sex-dependent exposure-related changes mucosa finding was new and surprising to us. not seen cigarette smokers these been observed before she noted. findings limited several factors including diversity of that could affect participants e-cigarette exposures e-liquid flavor type device nicotine content frequency use as well small sample size variations completeness questionnaires researchers wrote. when stratified gender s aureus more abundant women vs men they said but cross-sectional study design prevented measurement whether this increase correlated with increased disease risk. however results support previous research showing an effect inhaled toxicants on respiratory provide robust evidence said. regardless location linked a range diseases gut is now explored therapeutic target probiotics being example. tract some investigators suggested similar approaches explained. how may clues causes potential targets interventions added. current unable control non vaping devices such increasingly popular tetrahydrocannabinol jaspers. many users dual also vaped thc affects important area further given popularity early interesting resultsgiven persistence adolescents adults aimed address knowledge gap which plays crucial role health dharani k. narendra md baylor college medicine houston interview. dysbiosis particularly notable studies had demonstrated immune responses based extent manifest microbial composition unexpected. additionally discovery specific bacterial species behaved differently between highlighted distinct impacts key clinical takeaway from smoking are associated predispose infections dysfunction effects highlighting importance considering biological factor assessing risks should be aware without influence immunity ways differ traditional emphasized. can inform assessment patients their or habits implementation preventive measures protect against dysbiosis-related conditions limitations include relatively variability patterns levels types fact former might influenced expand cohort sizes account detailed usage parameters utilize advanced sequencing methods obtain higher-resolution insights into longitudinal needed investigate correlates development progression supported national institutes health. no financial conflicts disclose. disclose serves editorial board physician.>
Source : Medscape