Your mouth is a great place for micropests to dwell. Glistening white plateaus, dark crevices, and slimy surfaces boast steamy temperatures of 95 degrees Fahrenheit. The microbes bathe in a saliva-induced humidity of 100 percent, and eat a lavish diet of sugar and other carbohydrates. It’s so lush and varied, researcher Donna Mager refers to it as a mini-jungle. Mager is a fellow in oral medicine at the Forsyth Institute, an independent research institution in Boston. Forsyth scientists, most of whom are on the faculty of the Harvard School of Dental Medicine, have found 615 different species of bacteria – and they’re still counting. “In one mouth, the number of bacteria can easily exceed the number of people who live on Earth,” notes Sigmund Socransky, associate clinical professor of periodontology at Harvard. Years of detecting and identifying mouth tenants have revealed that those living in healthy mouths can be remarkably different from those living in diseased mouths. Some bacteria increase in number, while others decrease. By comparing communities of microbes in healthy people with those in the mouths of those with oral cancer, Mager has found a pattern that she expects will lead to the early diagnosis of oral cancers.