Effects of chlorhexidine mouthwash on the oral microbiome

Raul Bescos*, Ann Ashworth, Craig Cutler, Zoe L. Brookes, Louise Belfield, Ana Rodiles, Patricia Casas-Agustench, Gary Farnham, Luke Liddle, Mia Burleigh, Desley White, Chris Easton, Mary Hickson

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

80 Citations (Scopus)
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Following a single blind, cross-over and non-randomized design we investigated the effect of 7-day use of chlorhexidine (CHX) mouthwash on the salivary microbiome as well as several saliva and plasma biomarkers in 36 healthy individuals. They rinsed their mouth (for 1 min) twice a day for seven days with a placebo mouthwash and then repeated this protocol with CHX mouthwash for a further seven days. Saliva and blood samples were taken at the end of each treatment to analyse the abundance and diversity of oral bacteria, and pH, lactate, glucose, nitrate and nitrite concentrations. CHX significantly increased the abundance of Firmicutes and Proteobacteria, and reduced the content of Bacteroidetes, TM7, SR1 and Fusobacteria. This shift was associated with a significant decrease in saliva pH and buffering
capacity, accompanied by an increase in saliva lactate and glucose levels. Lower saliva and plasma nitrite concentrations were found after using CHX, followed by a trend of increased systolic blood pressure. Overall, this study demonstrates that mouthwash containing CHX is associated with a major shift in the salivary microbiome, leading to more acidic conditions and lower nitrite availability in healthy individuals.
Original languageEnglish
Article number5254
Number of pages8
JournalScientific Reports
Publication statusPublished - 24 Mar 2020


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