Does Being Too Clean Cause Allergies?Does practice make perfect for your body when it's fighting bacteria? The 'hygiene hypothesis' says so.Get more newsLiveonPrintApril 21, 2015, 4:40 PM UTC / Updated April 21, 2015, 4:40 PM UTC / Source: NBC NewsBy Maggie FoxMaggie FoxMaggie Fox is a senior writer for NBC News and TODAY, covering health policy, science, medical treatments and disease.
