Probiotics are a group of food and feed products and are also known as direct fed microbials. The concept was first written about in 1908 by a Russian scientist. He attributed the longevity of a group of Bulgarians to their consumption of fermented milk products. In 1960, an Oregon microbiology professor first used the term "probiotics," meaning "for life." As you might guess, this is the opposite of "antibiotic," or "against life."