Officially, probiotics are "live microorganisms which when administered in adequate amounts confer a health benefit on the host," according to the World Health Organization. In lay terms, probiotics are the healthy bacteria that inhabit your intestines and, many believe, form the basis of general health and wellness including digestion and immune function. These "friendly bacteria" go by such names as acidophilus and L. reuteri. Supplementing with them helps balance the overall ratio of good bacteria to bad bacteria. Supplementing with probiotics is particularly beneficial during and after the use of antibiotic drugs because the antibiotics kill off all bacteria in your gut and so it helps to repopulate yourself with good bacteria. Probiotics are right up there with omega-3 fish oil as the hottest-selling dietary supplements on the market today. On labels, their dosage levels are typically in the billions of CFUs, or colony-forming units. In foods, probiotics find their most compatible homes in dairy products such as yogurt. That’s because these products need refrigeration and have short shelf lives, which is also the state of affairs for these live bacteria.
Research into health benefits of probiotics is increasing at a rapid pace, yet is still in its infancy. Only since about 2005 has the research demonstrated that multiple probiotic strains are more effective than single strains, and only since 2009 has research shown that prebiotic fibers, such as inulin and FOS, improve the performance of probiotics. Even so, there is a great deal we still do not know, such as the specific health benefits of particular probiotic strains--not all probiotics are created equally--and which prebiotics match up best with particular probiotics.
