Fruit could deliver anti-tooth decay protein

A bowl of strawberries might one day be good for your teeth if scientists succeed in a plan to introduce an agent that can fight tooth decay.

A bowl of strawberries might one day be good for your teeth if scientists succeed in a plan to introduce an agent that can fight tooth decay.

Horticultural researchers are working with dental scientists to develop fruits that contain a small synthetic protein that prevents certain bacteria from sticking to teeth.

David James, professor of plant biotechnology at Horticultural Research International in East Malling, Kent, told the meeting that a toothfriendly fruit is one aim of a collaborative research project with scientists at Guy's Hospital in London.

Tooth decay is caused by a single bacterium, Streptococcus mutans, one of 200 microbes that live in the mouth. Scientists at Guy's have designed a peptide protein that acts as a "vaccine" by blocking the adhesive mechanism that anchors the bacterium to the sticky plaque coating the teeth. It leaves other, potentially beneficial, bacteria untouched. Professor James said: "It is a novel strategy and probably has wider implications in other disease. Instead of killing bacteria with antibiotics, you actually identify receptor sites on the bacteria you target and produce a peptide that prevents the bacteria from sticking to the sites they normally stick to.

"Our idea in the longer term is to have a means of delivery that involves a raw product. It can't be a processed product, otherwise the protein would be destroyed."

Clinical trials involving the coating of teeth with the antibacterial protein show that it can retain an effect for up to 80 days, but the problem is to find a way of delivering the agent in a product people can use, Professor James said.

"One possibility is to derive products from it, such as a mouthwash, for example, because [existing] mouthwashes are known to be totally ineffective. They kill all bacteria in the mouth, although only one bacterium causes tooth decay.

"These products ... would have to be regarded as pharmaceutical products and would need the appropriate regulation and safety testing. What we don't know is how much we can deliver and how much is actually needed," he said.

"Fruits don't normally contain much protein, so that could be one of our problems. To get the amounts we need is one of the big targets for the future."