Mouthwashes have long bragged about killing 99.9 per cent of germs in your mouth, but US researchers suggest this scorched-earth approach may harm oral health by eliminating beneficial bacteria along with the bad.
A study by these researchers at Rutgers Health in New York—and published in Frontiers in Oral Health—found that a naturopathic mouthwash containing herbal ingredients could selectively target disease-causing bacteria while preserving the protective microbes that help maintain healthy gums and teeth.
“It’s a paradigm shift,” senior author Georgios Kotsakis said.
“We’re moving from eradicating all bacteria to focusing on selectivity. We want to keep the good bacteria alive while targeting the bad.”
The researchers tested a natural mouthwash called StellaLife VEGA Oral Care rinse against two conventional products: the prescription mouthwash chlorhexidine and Listerine Cool Mint.
In Petri dishes, they exposed various oral bacteria to each rinse and monitored their growth over several days.
The natural rinse significantly reduced populations of harmful bacteria such as Fusobacterium nucleatum and Porphyromonas gingivalis, while allowing beneficial species such as Streptococcus oralis and Veillonella parvula to survive.
Chlorhexidine and Listerine showed no such selectivity, eliminating beneficial and harmful bacteria alike. Chlorhexidine was particularly aggressive, reducing some beneficial bacteria populations a million-fold.
“These good bacteria have important functions,” Kotsakis said.
“They synergise with your tissues. They actually kill some of the bad bacteria themselves.”
Of course, Petri-dish results don’t necessarily translate to mouths full of teeth, saliva and dietary sugars, Kotsakis added.
“Randomised clinical trials are the next step.”
