Common mouthwashes on the market often claim to kill 99.9% of oral bacteria, but the latest research warns that this “one-size-fits-all” approach to sterilization may destroy the beneficial bacteria that are essential to oral health while removing harmful bacteria.
Researchers at Rutgers University School of Health in New York, USA, pointed out in a study published in the journal Frontiers in Oral Health that a natural mouthwash containing herbal ingredients can kill pathogens while retaining “good bacteria” that help maintain healthy gums and teeth.
“This is a completely new idea,” said Georgios Kotsakis, senior author of the study. “We are moving from a comprehensive strategy of sterilization to a more selective approach – only removing harmful bacteria while protecting beneficial bacteria.”
The research team compared a natural mouthwash called StellaLife VEGA Oral Care with two traditional products: one is prescription-grade chlorhexidine, and the other is the cool mint flavor of the commercial brand Listerine.
In the experiment, scientists placed a variety of common oral bacteria in a petri dish, treated them with the above-mentioned mouthwash, and observed their growth changes within a few days.
The results showed that natural mouthwash significantly reduced the number of harmful bacteria such as Fusobacterium nucleatum and Porphyromonas gingivalis, while having little effect on beneficial bacteria such as oral Streptococcus and Veillonella parvum, showing strong selectivity.
Chlorhexidine and Listerine showed a broad-spectrum bactericidal effect, eliminating both good and bad bacteria. Chlorhexidine, in particular, is extremely destructive to beneficial bacteria, and can even reduce their number by a million times.
“These beneficial bacteria are not insignificant,” Kotsakis pointed out. “They work with human tissues to fight pathogens and play a key role in maintaining oral health.”
However, the researchers also reminded that this experiment is still in the laboratory stage, and the actual oral environment is far more complex than the petri dish, and also involves factors such as saliva, tooth structure and eating habits.
“The next step is to initiate a randomized clinical trial to validate the applicability of these results in the real world,” Kotzakis added.