Print This Page Email This Page See Most Sent

• July 4 Cheers Can Echo Worldwide • Surf's Up! What Are the Top 10 Beaches in America? • 'Runaway Bride' Julia Roberts Ties the Knot

June 28

— WASHINGTON (Reuters) - Bacteria normally found in cheese can be souped up and used as a kind of guided missile to carry in defenses against dental cavities, European researchers said on Friday.

The Lactobacillus bacteria are commonly used in food supplements, are safe and easy to grow, so the researchers believe they may be a good option for a kind of anti-cavity vaccine.

The researchers, led by Carina Kruger and Lennart Hammarstrom of Sweden's Karolinska Institute, started out with antibodies that have been shown to work against the Streptococcus mutans bacteria -- the main culprit in dental caries -- the dentist's term for cavities.

But they do not last long in the mouth.

Writing in the journal Nature Biotechnology, the team of Swedish, Dutch and British researchers said they genetically engineered lactobacilli to produce the antibodies.

They chose lactobacillus because it has shown promise as a potential oral vaccine, and some studies suggest it has positive effects on the immune system.

Tests in rats showed the supercharged bacteria reduced the number of bacteria in the rats' mouths and also reduced the number of cavities.

And the Lactobacillus persisted in the mouth for three weeks, continually fighting the Streptococci. They tested 19 rats, removing their salivary glands and then swabbing the insides of their mouths with either plain water or water carrying the souped-up bacteria. Animals that do not produce saliva quickly develop cavities.

Then they infected the rats with mouthfuls of streptococci bacteria.

The treated rats got daily doses of Lactobacillus in their drinking water, and all the animals got extra sugar in their rat chow. When they were 42 days old they were killed and their mouths examined.

"S. mutans bacteria counts and caries scores were markedly reduced," the researchers wrote in their report.

They hope their approach will be "of considerable commercial interest," especially as Lactobacilli do not require U.S. Food and Drug Administration approval.

Copyright 2002 Reuters News Service. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.