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Living in harmony with bacteria

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December 31st, 2008

Bacteria are all over the place in soil, air, water, food, and us. In fact, there are so many bacteria living on and in our bodies that researchers haven t discovered them all. Don t start trying to scrub them off just yet. While bacteria may get a bad rap for causing sickness, many of these cells are essential to keeping us healthy. ' Balanced living "Most of the time we live in harmony with bacteria," says Mary Norman, M.D. Bacteria live throughout the human body and are concentrated in the mouth, gastrointestinal tract, vaginal tract, and on the skin. The mouth alone is home to 10 to 50 billion bacteria. The "good" bacteria coat and shield the mouth from harmful bacteria that may try to take over. When we eat sugar, we introduce other bacteria that produce acid. This acid can cause tooth decay and gum disease, the most common bacterial diseases in humans. "The best way to promote good bacteria is to maintain balanced nutrition," says Joan Slonczewski, Ph.D., professor of biology at Kenyon College in Gambier, Ohio. When it comes to digesting food, bacteria are there to help. "Intestinal bacteria live off the mucus in our intestines, helping prevent excess mucus buildup. They also stimulate the development of our immune systems," says Slonczewski. In addition to keeping everyone s digestive systems in good working order, bacteria keep women s health in check too. "Vaginal yeasts keep the pH low, preventing the growth of harmful bacteria," says Slonczewski. ' Invisible guests Because it s our outermost layer, skin gets exposure to all kinds of bacteria from the environment. "Staphylococcus epidermidis [staph] is the most common. It grows on our skin and helps protect us from bad bacteria," says Slonczewski. "But other kinds of staph can make us sick. "Any kind of bacteria that gets through the skin into the blood vessels can grow and make us sick, unless our immune systems eliminate them. As we age, our immune systems weaken, so it becomes increasingly important to avoid getting bacteria through the skin barrier into the body," Slonczewski adds. How can people ward off the "bad" bacteria and keep their skin barrier intact? "Gently wash skin with soap once a day to eliminate newly acquired bacteria that might be harmful," says Slonczewski. "But don t wash too often it dries out the skin. Then dry skin cracks, allowing harmful bacteria to enter. Use moisturizer to keep skin healthy and free from cracks, avoid wounds and scratches, and maintain overall health through exercise and nutrition, sustaining a strong immune system." ' The anti s When "bad" bacteria get past our skin and cause infections in our bodies, doctors may prescribe antibiotics as treatment. "The antibiotics we choose are targeted to our most likely suspicions for the bacteria. For instance, some bacteria only appear in urine. And a certain antibiotic is targeted to attack the bacteria common in urine infections. You might have a totally different type of antibiotic for a lung infection," says Norman. However, using antibiotics may disrupt the balance in our bodies. "Often, they will kill the good bacteria too," Norman adds. "For example, people treated for pneumonia will develop diarrhea because we ve killed off the good bacteria that help digest food normally." Washing with antibacterial soap also kills off bacteria that could be helpful. "Antibiotics and antibacterial soaps are not to be used continuously in the absence of disease/infection," says Janko Nikolich-Zugich, M.D., Ph.D., chair of the department of immunobiology at the University of Arizona. "Only when there is a bacterial disease should one be using antibiotics. Antibacterial soaps should be used mostly if there are outbreaks of bacterial diseases or in operating rooms where hands need to be disinfected. Otherwise, they will disturb the right balance and eventually help the wrong bacteria take over. "Regular soaps are just fine in most cases," he adds.

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