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Stinkers. Bacteria such as Klebsiella pneumoniae, shown here growing on a culture plate, can foul your breath.


Halitosis Alert

"Even your best friends won't tell you," a classic mouthwash ad warned. But OkayToKiss will bluntly let you know if your mouth is foul.

The new, patent-pending saliva test, developed by microbiologist Mel Rosenberg of Tel Aviv University in Israel and colleagues, turns blue if it senses high quantities of certain bug enzymes. The research behind the product is reported in the latest Journal of Breath Research. In the past, one microbial group, the Gram-negative bacteria, has taken all the blame for dragon breath. But Rosenberg and his team analyzed bacteria in incubated saliva samples and found that members of the other main bacterial group, the Gram-positives, help out by producing enzymes that make it easier for Gram-negative bacteria to break down proteins into stinky compounds.

OkayToKiss is one byproduct of a boom in research on the microbiology of odors, says Rosenberg. At the first-ever symposium on the field held last week at the meeting of the American Society for Microbiology in Philadelphia, Pennsylvania, he and about 150 other scientists discussed the tiny lives that underlie flatulence, manure, livestock, and pet odors. "You need to know who's living there first in order ... to try and inhibit these bacteria, whether in the mouth, in manure, or in the intestinal tract," says the symposium's co-organizer, Terence Whitehead, a microbiologist with the U.S. Department of Agriculture in Peoria, Illinois. Whitehead notes that when he and colleagues recently analyzed the bacteria in swine manure, they found that "probably 90% of them had never been seen before."