Before you stock up on cranberries and garlic, keep in mind that these foods aren't meant to replace antibiotic drugs, but rather they're foods that contain important compounds that can restore the good and bad bacteria in your body, Dr. Li says. "In the last 10 years in the medical field, we're still changing from the concept of, All bacterias are bad and we've got to kill them all, to, Actually, we really need to restore the balance of bacteria," she says. If you have a mild illness, like if you think you're getting a cold, then eating some of these will help "bring the garden back to beautiful bloom and harmony," she says. But for more serious infections, you've got to go see a doctor, so they can figure out the exact thing causing it and treat it with a targeted medication.