Ever since nomadic tribes helped spread wild garlic from Central Asia to far-flung parts of the globe, garlic has helped humans fight microbes. Louis Pasteur recognized its antimicrobial power, as did doctors in WWI and WWII battlefield hospitals, where injured soldiers were given garlic to prevent infection and gangrene. Today's warnings of a "post-antibiotic" future mean garlic's power may turn out to be handy as drug-resistant bacteria become widespread. ( Podcast : " The Plant Detective ,"