When it comes to freshening your breath, you've probably tried it all: mouthwash, mint gum, Altoids, Tic-Tacs®, brushing and flossing religiously, or even some more exotic remedies like tongue-scraping. But have you tried adding more bacteria to your mouth?

That may be the best solution, argues Deborah Franklin in May's issue of Scientific American, according to the latest evidence in studies and research from around the globe. It turns out that if you want to counteract offending germs and their smelly byproducts, you are better off nurturing helpful bacteria, rather than fighting the bad guys.

Bad breath is scientifically proven. Researchers have identified about 150 molecular components typically contained in a single human breath, with a couple of key offenders: hydrogen sulfide, which smells like rotten eggs, and methyl mercaptan, which smells like rotten cabbage.

If you are sensitive, you may want to skip the next few sentences.

These (and other foul-smelling compounds) are waste products of the millions upon millions of "gram-negative" bacteria that live in your mouth, feasting on tiny food particles and gum tissue. Gram-negative bacteria have an impenetrable cell wall, and are more resistant to antibodies than their cousins, gram-positive bacteria. They are resilient creatures, thriving in the spaces between the gum and teeth, and in the crevices of your tongue.

What makes things even more complicated is that it isn't any one type of bacteria acting solo that leads to bad breath - it's more of a community effort.

"Fresh breath reflects a healthy mouth, which is not necessarily one that lacks 'bad' breath...but rather one in which overlapping bacteria colonies hold one another in check," writes Franklin.

And everyone's mouth has a slightly different colony. Bacterial geneticists working on the Human Microbiome Project have determined that there are over 1,000 species of bacteria that can show up in the human mouth. However, each individual person has "maybe 100 to 200 of those bacterial species colonizing their mouth at any given time," said Dr. Wenyuan Shi, a correspondent for the project at the University of California, Los Angeles.

Currently, the most effective way to fight odor-causing bacteria is by using prescription mouth rinses containing chlorhexidine or other antiseptic, which "carpet-bomb" the mouth, killing off all bacteria.

But you don't want to just destroy your entire bacteria colony. In doing so, you might expel the good with the bad, leading to a higher risk for other, more aggressive species coming in and leading to infections and possible gum disease.

So, researchers are looking at a few different potential solutions.

The term "probiotics" has been tossed around a lot lately in reference to easing stomach issues, but its relevant here, too. Probiotics basically mean adding helpful bacteria species to a colony. To help cure bad breath, researchers are looking at a gram-positive bacterial species called Streptococcus salivarius K12. The K12 species is safe, and is thought to produce substances that quell bad bacteria. A recent study asked volunteers to gargle with a chlorhexidine mouthwash and then suck on a K12 lozenge. After seven days and 14 days, all the subjects reported having better smelling breath.

Shi suggested that researchers could also develop a mouthwash containing a peptide designed to target and destroy the bacteria behind bad breath. This would help alter the colony without resorting to a carpet-bombing.

But until these are developed, what's a person with bad breath to do? Perhaps you can take the advice of Hippocrates, who, 2400 years ago, recommended wine, anise, and dill seed to maintain fresh breath. Or just keep brushing and flossing daily.