A Bacteria That Could Keep Your Mouth Clean for Good

Feb. 20 -- Dental care could soon involve a process as simple as this: Rinse once, feed bacteria.

A Florida researcher is hoping to soon begin clinical trials for his bacterial rinse that's designed to stave off tooth decay for a person's lifetime. So far, the rinse has worked in rats and early prototypes have been tested in three people.

"You would just need to squirt onto tooth surfaces once," said Jeffrey Hillman a professor of oral biology at the University of Florida in Gainesville.

Bacteria, he explains, take care of the rest.

The rinse could be a wonderfully simple approach to dental care, although some worry that introducing a modified microbe directly into the body could lead to trouble.

Building a Bug Weapon

Most tooth decay is caused by a particular strain of bacteria called Streptococcus mutans (S. mutans). While 500-600 different kinds of bacteria thrive on mucus and food remnants in the mouth, S. mutans is particularly damaging because it consumes sugar (mostly refined sugars) on the surface of teeth and converts it to lactic acid. The lactic acid is what eats away at a tooth's enamel.

In the early 1980s, Hillman set out to find a bacterium that might destroy the decay-causing strain. After taking hundreds of sample swabs from patients' mouths, he found a bacterium that secretes a toxin that kills S. mutans.

Hillman and his colleagues then altered a gene in the bacterium so it would not secrete lactic acid of its own. Recently they tweaked the bacterium again so it would only survive if fed a particular nutritional supplement. That ensures the bacterium won't spread from one person to another while kissing or sharing utensils.

"Subjects will have to chew gum or use mouthwash to provide the bacteria with its nutritional supplement," said Hillman.

When Hillman squirted the strain on rats, the substance appeared to prevent tooth decay in the animals for the entire six-month period of the tests. He has also squirted a version of the bacterium on three human volunteers.