The impact of vaping behavior on functional changes within the subgingival microbiome.

The use of Electronic Nicotine Delivery Systems (ENDS), or vaping devices, has raised concerns about their potential impact on oral health, particularly periodontal disease. While traditional smoking is a well-established risk factor for periodontal disease, the biological and microbial effects of ENDS use are less well understood. Our study examined how vaping and vaping behaviors influence the subgingival plaque microbiome and the associated metabolic pathways that may contribute to oral disease. We enrolled 70 healthy adults aged 18-35, including 48 regular ENDS users and 22 non-vaping controls. ENDS users were categorized by puffing behavior into low, medium, and high flow groups using a validated topography device. All participants underwent periodontal screening and provided saliva and subgingival plaque samples. To evaluate exposure profiles, ENDS users also submitted their personal devices for emissions testing, and volatile organic compounds (VOCs) were collected and analyzed using gas chromatography-mass spectrometry and high-performance liquid chromatography. Compared to non-vapers, ENDS users demonstrated distinct shifts in their oral microbiome, with reductions in beneficial taxa and increased bacteria associated with inflammation and periodontal disease. These changes were more pronounced in high-puff volume users, who also exhibited lower microbial diversity. Functional profiling revealed vaping-associated enrichment of pathways related to lipid metabolism, inflammation, and xenobiotic degradation. Untargeted salivary metabolomics identified metabolic disruptions consistent with these functional shifts. Integrative network analyses incorporating VOC measurements demonstrated correlations between microbial composition, puff volume, and metabolic disruptions, particularly in lipid-regulated and inflammatory pathways. To our knowledge, this is one of the first studies to integrate vaping behavior, oral microbiome profiling, salivary metabolomics, and VOC emissions analysis in a human cohort. These findings suggest ENDS use, especially at higher intensities, may disrupt oral microbial and metabolic homeostasis through both biological and chemical pathways potentially enhancing periodontal disease risk. These patterns point to potential biological and chemical pathways of concern, warranting further investigation and informing public health priorities.