Abstract
BACKGROUND: Although touted as a safer alternative to cigarette smoking, electronic cigarette usage has been increasingly linked to a myriad of health issues and appears to impact the oral microbiome. Meanwhile, nitrate supplementation has shown promise as a prebiotic that induces positive effects on the oral microbiome. METHODS: In this pilot study, the impact of nitrate supplementation as a countermeasure to e-cigarette usage was explored using in vitro growth and 16S rRNA analysis of microcosms derived from e-cigarette users and nonusers and supplementation with nitrate-rich beetroot juice extract. RESULTS: The impacts of e-cigarette usage and beetroot supplementation were somewhat limited, with beetroot juice extract supplementation having a significant impact on diversity according to some, but not all, diversity metrics examined. The saliva of the e-cigarette users was depleted in nitrate-reducing Neisseria spp. In terms of differentially abundant individual taxa, the addition of beetroot juice extract to the saliva-derived microcosms had a larger impact on the communities derived from the e-cigarette users compared to that of the nonusers. CONCLUSIONS: Overall, this limited pilot study suggests that beetroot juice extract supplementation may impact the microbiota of e-cigarette users and adds to contemporary research paving the way for more in-depth studies examining the role of nitrate-rich supplements as prebiotics to promote oral health.