Mouthwash May Change Oral Microbes

The use of chlorhexidine mouthwash may increase the abundance of lactate-producing bacteria that lowers salivary pH and potentially increase the risk of tooth damage, according to research led by the University of Plymouth’s Faculty of Health in England. The research is published in Scientific Reports. 

Researchers gave a placebo mouthwash to subjects for 7 days, followed by 7 days of a chlorhexidine mouthwash. They then conducted an analysis of the abundance and diversity of the bacteria in the mouth and measured pH, saliva buffering capacity, lactate, glucose, nitrate and nitrite concentrations.

After 7 days, researchers found using chlorhexidine mouthwash led to a greater abundance of species within the families of Firmicutes and Proteobacteria, and fewer Bacteroidetes, TM7 and Fusobacteria. This change was associated with an increase in acidity, seen in lower salivary pH and buffering capacity, according to the study.