Gargling with an antiseptic mouthwash may help Type 2 diabetes patients reduce the number of periodontitis-related bacteria, suggests a study.

There is growing evidence that ongoing inflammation in the mouth, such as that seen in gum disease, in addition to causing bad breath is associated with serious diseases such as Alzheimer's Disease or Type 2 diabetes.

Researchers from the Osaka University in Japan showed gargling may be a solution.

In addition, some patients with reduced bacteria also achieved much better control of their blood sugar, hinting at promising future clinical applications, they noted in the study published in the journal Scientific Reports.

"There are three highly virulent bacterial species that are linked to periodontitis, or diseases of the tissues surrounding the teeth," said lead author Saaya Matayoshi from the varsity.

"We decided to see if we could reduce these three species -- Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia -- in patients with Type 2 diabetes using a mouthwash containing the antiseptic chlorhexidine gluconate," Saaya added.

To see whether gargling itself was effective for reducing bacteria, or whether mouthwash was more effective, the study participants first gargled with water for six months, and then with the antiseptic mouthwash for the next six months.

"We were unsurprised to see that gargling with water had no effects on bacterial species or HbA1c levels," explained Kazuhiko Nakano, from the varsity.

"However, there was an overall reduction in bacterial species when the patients switched to mouthwash, as long as they were gargling at least twice a day," Nakano added.

While the results showed no overall changes in HbA1c levels, when patients gargled with the antiseptic mouthwash, there appeared to be large variations in individual responses.

For example, when they split the group into younger and older patients, younger patients had greater reductions in bacterial species and significantly better blood-sugar control with mouthwash compared with water.

Given that poor oral health is linked to serious disease, simple methods to improve oral hygiene have important ramifications.

This easy-to-use treatment may also improve the lives of people with periodontitis-linked diseases such as diabetes, dementia, cardiovascular disease, and respiratory tract infections, said the team.