The first-ever study on examining the aftereffects of chlorhexidine-based mouthwash has revealed shocking results. It says that the total microbiome of the oral cavity is affected whenever a person uses a mouthwash. This change is marked with a rapid increase in certain lactate-making bacteria which reduce the total pH of the saliva and oral cavity. This acidic pH might put dental health to risk by causing damage to the teeth.
The complete details of this study are published recently in the journal “Scientific Reports”.
A research team from the University of Plymouth, led by Dr. Raul Bescos investigated the effects of using a mouthwash by giving it to seven study subjects. First, they tested a placebo product for one week and after that, they gave them a chlorhexidine based mouthwash for one week.
By the end of every week, they completed the microbiome analysis of these subjects’ mouths and checked the type and abundance of bacteria inside. They also checked the pH, lactate, nitrate and glucose concentrations in the oral cavity as well as the saliva buffering capacity of every participant.
The results suggest that using a chlorhexidine-based mouthwash for at least seven days causes certain bacteria to overgrow. These bacteria were from the family Firmicutes and family Proteobacteria also some Bacteroidetes, TM7 and Fusobacteria too. Researchers have reported a change in acidity, pH, and saliva buffering capacity.
It shows that using a chlorhexidine-based mouthwash can affect reduced diversity in oral microbe, although these results are inconclusive and it needs more in-depth analysis but still it is sufficient to determine that these mouth wash can cause certain disease in its users.
Typically, saliva is responsible for maintaining the overall pH of the mouth. When a person eats or drinks certain foods, the pH of mouth changes but eventually it is maintained by the saliva. But if saliva pH decreases to such a low level, it could affect the mucosal lining and eventually teeth.
Some previous researches indicated that chlorhexidine can damage the natural capacity of some bacteria from the oral cavity to make nitrite from nitrates. For those who don’t know, this conversion is essential to maintain and reduce high blood pressure.
So a low saliva pH and compromised potential of conversion to nitrite are already associated with this chlorhexidine mouthwash. This new research confirms these effects. In addition to this, it also confirms that the bp controlling effect that is typically associated with exercise is also affected when people use an antibacterial mouthwash instead of using plain water.
Dr. Zoe Bescos, a co-author of this research says that:
“There is a surprising lack of knowledge and literature behind the use of these products. Chlorhexidine mouthwash is widely used but research has been limited to its effect on a small number of bacteria linked to particular oral diseases, and most have been carried out in vitro.”
She also shared that; “we believe this is the first study to look at the impact of 7-day use on the whole oral microbiome in human subjects.”
Dr. Louise Belfield, another co-author of this study teaches at Peninsula Dental School of the University of Plymouth.
Dr. Belfield shared that;
“We have significantly underestimated the complexity of the oral microbiome and the importance of oral bacteria in the past. Traditionally the view has been that bacteria are bad and cause diseases. But we now know that the majority of bacteria—whether in the mouth or the gut—are essential for sustaining human health.”