Whether you're about to kiss your girlfriend or begin a job interview, how would you know whether your breath is sweet and clean.
Tel Aviv University (TAU) researchers have come up with a tiny breath test which lets you know whether malodorous bacteria are swarming all over your mouth. A blue result suggests you need a toothbrush. But if it's clear, you're "okay to kiss".
The original 'OkayToKiss device' comprises a colour indicator and saliva collector.
Scientists believed that only one population of bacteria (the gram-negative ones) break down the proteins in the mouth and produce foul odour.
But Mel Rosenberg, professor and Nir Sterer of TAU's Sackler Faculty of Medicine, recently discovered that the other population of bacteria (the gram-positive ones) are bad breath's bacterial partner.
These bacteria appear to help the gram-negative ones by producing enzymes that chop sugary bits off the proteins that make them more easily degraded. This enzymatic activity, present in saliva, serves as the basis for the new "OkayToKiss" test.
Rosenberg, an authority on the diagnosis and treatment of bad breath, co-developed the kit with Sterer. An earlier invention of Rosenberg led to the development of two-phase mouthwashes that have become a hit in Britain, Israel and elsewhere.
"All a user has to do is dab a little bit of saliva onto a small window of the 'OkayToKiss' kit," explained Rosenberg.
"'OkayToKiss' will turn blue if a person has enzymes in the mouth produced by the gram-positive bacteria. The presence of these enzymes means that the mouth is busily producing bacteria that foster nasty breath," he explained.
Apart from its social uses, the test can be used as an indicator of a person's oral hygiene, encouraging better health habits, such as flossing, brushing the teeth, or scheduling that long-delayed visit to the dentist, said a TAU release.
These findings were published in the Journal of Breath Research.