Matcha mouthwash inhibits bacteria that cause periodontitis

Periodontitis is an inflammatory disease of the gums caused by a bacterial infection that, if left untreated, can lead to complications including tooth loss. The disease is also associated with diabetes, premature birth, cardiovascular disease, rheumatoid arthritis and cancer. One of the main bacterial pathogens of periodontitis is Porphyromonas gingivalis, which colonizes biofilms on the surface of teeth and multiplies in deep periodontal pockets.

Matcha, a finely ground green tea powder, may help control P. Gingivalis. In the journal Microbiology Spectrum, Japanese researchers reported that matcha inhibited the growth of P. Gingivalis in laboratory experiments. Additionally, in a clinical study of 45 people with periodontitis, people who used matcha rinse had significantly lower levels of P. Gingivalis in saliva samples compared to the start of the study.

“Matcha may have clinical applications for the prevention and treatment of periodontitis,” note the authors of the article.

Camellia sinensis is a green tea plant that has long been studied for its potential antimicrobial effects against bacteria, fungi, and viruses. A previous study in mice found that green tea extract could inhibit the growth of pathogens, including Escherichia coli.

Other studies have shown that the extract can inhibit the growth of P. Gingivalis and reduce its adhesion to oral epithelial cells. Additionally, observational studies have linked green tea consumption to improved health.

Matcha, which is used in traditional ceremonies and to flavor drinks and sweets, is made from the raw leaves of C. Sinensis.

In a new study, scientists from Nihon University's Faculty of Dentistry in Matsudo, the National Institute of Infectious Diseases in Tokyo and other institutions conducted a series of in vitro experiments to test the effectiveness of matcha solution against 16 species of oral bacteria, including three strains of P. Gingivalis. Matcha rinse showed low activity against commensal oral bacterial strains.

Within two hours, almost all cultured P. Gingivalis cells were killed by matcha extract, and after four hours of exposure, all cells were dead. These results indicate bactericidal activity against the pathogen.

The researchers then recruited 45 people diagnosed with chronic periodontitis at the Nihon University Dental Clinic in Matsudo for a follow-up clinical study.

Patients were randomly assigned to three groups: one group received a barley tea rinse, one received a matcha extract rinse, and the third received a rinse containing sodium azulene sulfonate hydrate, which is used to treat inflammation. Saliva samples were collected before and after the intervention and analyzed by PCR, and participants were instructed to rinse their mouth twice daily.

The analysis showed that patients who used the matcha rinse had a significant reduction in P. Gingivalis levels. Patients in the other two groups did not experience such a significant reduction.

Although the new study is not the first to examine the antimicrobial effects of tea-derived compounds on P. Gingivalis, the researchers note that it supports the potential benefits of matcha as part of a treatment plan for people with periodontitis.