What Qualifies as a Probiotic?

Live dietary microbes are found on fresh fruits and vegetables and in a variety of fermented foods – but within this category, only some microbes have the special status of “probiotic”. Microorganisms must meet certain scientific criteria to qualify as a true probiotic: there must be scientific evidence showing a health benefit for a human (or other host) and that evidence must match any claim made on the label; it must be safe for its intended use; it must be scientifically identified by its genes and properly named; and a specimen must exist for the use of other researchers.