A common antibacterial substance found in toothpaste may combat life-threatening diseases such as cystic fibrosis, when combined with an already approved drug, a study has found.
Researchers at Michigan State University in the US have found that when triclosan, a substance that reduces or prevents bacteria from growing, is combined with antibiotic tobramycin, it kills the cells that protect the cystic fibrosis (CF) bacteria, known as Pseudomonas aeruginosa, by up to 99.9 per cent.
CF is a genetic disease with one in every 2,500 to 3,500 people diagnosed with it at an early age, according to the study published in the journal Antimicrobial Agents and Chemotherapy.
It results in a thick mucus in the lungs, which becomes a magnet for bacteria, researchers said.
These bacteria are notoriously difficult to kill because they are protected by a slimy barrier known as a biofilm, which allows the disease to thrive even when treated with antibiotics.
"The problem that we are really tackling is finding ways to kill these biofilms," said Chris Waters, a professor at Michigan State University.
According to Waters, there are many common biofilm-related infections that people get such as ear infections and swollen, painful gums caused by gingivitis.
However, more serious, potentially fatal diseases join the ranks of CF including endocarditis, or inflammation of the heart, as well as infections from artificial hip and pacemaker implants.
Waters and colleagues grew 6,000 biofilms in petri dishes, added in tobramycin along with many different compounds, to see what worked better at killing the bacteria.
Twenty-five potential compounds were effective, but one stood out.
Triclosan has been used for more than 40 years in soaps, makeup and other commercial products because of its antibacterial properties.
Recently, the US Food and Drug Administration (FDA)ruled to limit its use in soaps and hand sanitisers due to insufficient data on its increased effectiveness and concern that it was being overused.
Clear evidence has shown, though, that its use in toothpaste is safe and highly effective in fighting gingivitis, and it is still approved for use, researchers said.
Tobramycin is currently the most widely used treatment for CF, but it typically does not clear the lungs of infection, Waters said.
Patients typically inhale the drug, yet find themselves chronically infected their whole lives, eventually needing a lung transplant.