It's understandable that parents want to keep their children's environments clean, especially when kids are young. Moms wash bottles in hot water, clean pacifiers that fall on the ground, and take dirty things out of their kids' mouths.But overall, when it comes to germs, most people have it backward: With relatively few exceptions, they are good for our kids. Keeping things clean is smart, but going crazy using antibacterial hand soaps, buying antibacterial kids' toys and other products, and overusing antibiotic medications is actually killing off the microbes that can help strengthen the immune system.Antibacterial products may help to reduce some infections, but they also promote the growth of drug-resistant organisms and weaken the good bacteria within us. Rather than focus on killing germs, we need to think about how to encourage their growth.Supporting the “right” bacteria can have a huge health payoff for your kids: fewer ear infections, tummy aches, episodes of diarrhea, urinary-tract infections, and food allergies. It can even help kids fight off coughs, colds, and fevers. Here's how to ensure your kids have enough of the good stuff:Feed your kids right: Give them foods that naturally contain helpful organisms. These include yogurt, pickles, dark chocolate, and feta cheese. In some cases , it may be useful to give a probiotic supplement (available at most pharmacies and health-food stores) containing beneficial live bacteria.All of these foods and supplements are fine to give kids starting at around 6 months. There are other foods to include in their diet that don't actually contain good germs but help to nurture them: garlic, onions, asparagus, whole oats, whole wheat, honey (for children over age 1), and bananas.Make safe and smart choices: Keep your kids away from cigarette smoke; exposure can kill off favorable bacteria. As for antibiotic drugs, don't insist that your pediatrician prescribe them when he says they're not necessary. These drugs eliminate both good and bad bacteria. If your kids do have to take antibiotics, make sure they get probiotics, too, to restore the body's supply of good bacteria.Keeping the body's bacteria in balance doesn't take a lot of effort, but it can have big benefits. Starting these habits young can help keep kids healthy for life.