Can mouthwash repel gonorrhoea? Trials show positive results

Researchers in Australia demonstrate that Listerine kills off bacteria that causes disease

The researchers set out to see if Listerine could curb the growth of N gonorrhoeae involving 33 men from among 196 bisexual and gay men who had previously tested positive for the bacterium. Photograph: Getty Images

The researchers set out to see if Listerine could curb the growth of N gonorrhoeae involving 33 men from among 196 bisexual and gay men who had previously tested positive for the bacterium. Photograph: Getty Images

 

Your morning mouthwash gargle does more it seems than deliver fresh breath. It has also emerged as a low-cost way to help control the spread of sexually transmitted diseases.

Researchers in Australia showed in the lab and in a human trial that the popular mouthwash Listerine is strong enough to kill off the bacteria that cause gonorrhoea.

The study by a sexual health clinic in Melbourne found that daily rinsing and gargling with the product reduced the bacterial count in the mouth and throat. The study authors suggest use of the mouthwash offered a cheap and easy way to help control the spread of the organism, Neisseria gonnorhoeae.

This might seem like a novel new approach but not at all. As far back as 1879 the manufacturer of Listerine offered its product as a way to cure gonorrhoea, but there were no studies to back this up.

The Melbourne Sexual Health Centre in Victoria has now filled this gap, publishing the findings in the journal Sexually Transmitted Infections.

This is not a small finding given the only viable alternative treatment is the use of antibiotics and the most common preventative measure is the use of condoms.

Clinical study

Antibiotic resistance is an increasing problem, however, and condom use is in decline, the authors write. The result is new cases are on the rise, particularly amongst gay and bisexual men, the researcher say.

The researchers set up a parallel lab and clinical study to see if Listerine could curb the growth of N gonorrhoeae involving 33 men from among 196 bisexual and gay men who had previously tested positive for the bacterium.

Various dilutions of Listerine Cool Mint and Total Care – which contain 21.6 per cent alcohol – were tested in the lab and shown to “significantly reduce” bacterial numbers, the researchers said.

The 33 men were given either Listerine or a simple saline solution and asked to rinse and gargle for a minute. This knocked out the number of viable bacteria by half in those using Listerine but by only 16 per cent in those using saline, the authors report.

The results were so good a larger trial is under way to see if the mouthwash could help reduce the spread of gonorrhoea.

If the trial proves positive “then this readily available, condom-less and low-cost intervention may have very significant public health implications in the control of gonorrhoea”, the researchers write.