When you're devouring Thanksgiving foods, the bacteria in your mouth are feasting too.Our mouths are full of bacteria. Hundreds of different kinds live on our gums, teeth, tongue and cheeks. While some bacteria are helpful, others can cause harm, such as those that play a role in tooth decay. To say sugar is the main cause of cavities isn't quite the whole story. While it can do nasty damage to teeth, the leading cause of dental caries is called Streptococcus mutans, or S. mutans, which is a type of bacteria that lives in your mouth. In fact, it falls under the category of anaerobic bacteria, meaning that it can live without oxygen - think of anaerobic workouts, such as weight lifting, which doesn't consume a lot of oxygen, and aerobic workouts, such as long-distance running, which are known to lead to huffing and puffing. Let's take a look at the science behind S. mutans. This troublesome bacterium splits sugars in foods and uses them to build its own little capsule, which sticks tightly to the teeth. The bacteria produce a strong acid that attacks enamel and starts to erode the tooth. If the acids are not removed, it can end up creating tiny holes in the tooth - what we all know as cavities. So, how do cranberries help protect against dental caries? When you're scooping delicious stuffing, turkey and gravy onto your plate at dinner time, don't forget about cranberries! These red berries have been proven to contain a boatload of antioxidants and can help fight off dental plaque. A team from the University of California at Los Angeles and Oceanspray Cranberry showed that the flavonoids quercetin and myricetin in cranberries prevent S. mutans bacteria from sticking to teeth, thereby reducing the amount of cavities. After all, tooth decay is the most common oral problem that Americans experience each year, with more than 90 percent of adults ages 20 to 64 having dental caries in their teeth, according to the National Institute of Dental and Craniofacial Research. With all the sugars, sweets and constant eating that come with Thanksgiving, it's important to opt for some of the healthier food choices. Cranberries beat out most other fruits and vegetables with a significant amount of disease-fighting polyphenols, or antioxidants - second only behind blueberries. Not even spinach, red grapes, apples or cherries have as much as these tasty berries. They pack in vitamin C and fiber as well, and are only 45 calories per cup. Besides protecting your teeth, cranberries have anti-inflammatory and anti-cancer benefits, which protect against free radicals, and help defend our cardiovascular systems and livers. In fact, cranberries are so healthy for you that scientists are working on extracting the cavity-fighting compounds in cranberries. Dr. Hyun Koo, a researcher for the Center for Oral Biology and an associate professor in the Eastman Institute for Oral Health, has identified molecules known as A-type proanthocyanidins?. These substances contain the potential to reduce caries dramatically. After multiple tests, Dr. Koo discovered that when the molecules were applied, glucan and acid production by S. mutans was slashed by up to 70 percent while cavity formation was reduced by up to 45 percent. Koo is even looking to incorporate them into mouth rinses or toothpastes to help get rid of anaerobic bacteria and dental caries. "Maintaining the natural balance of resident flora in the oral cavity is important for keeping opportunistic pathogens in check," Koo told Science Daily. "These molecules don't outright get rid of S. mutans. Instead, they disrupt the two most harmful actions of this pathogenic organism, acid production and glucan production." After your Thanksgiving feast is finished, save your cranberries for later. Fresh cranberries kept in a tightly sealed container in the refrigerator last up to two months, while cooked cranberries will last one month. Though it is a staple of Turkey Day, you should enjoy cranberries year-round!