Q: Our pediatrician told me that using antimicrobial soaps and oversanitizing our house could give my 4-year-old son asthma later in life. Is he kidding? – Grace P., Minneapolis

A: Bacteria — even disease-causing bugs — are important for good health. The indiscriminant annihilation of those little creatures may deny a young’un’s developing immune system the opportunity to meet its adversaries and build its germ-fighting muscles properly.