Probiotic Safety—No Guarantees

Abstract

For centuries, people have consumed live bacteria in many foods, such as yogurt, cheese, kimchi, and sauerkraut. The mass-marketing of isolated live bacteria for their purported beneficial or “probiotic” properties, however, is a relatively recent phenomenon. The World Health Organization defines probiotics as “live microorganisms which when administered in adequate amounts confer a health benefit on the host.” Yet to be sold as a probiotic supplement in the United States, a live microorganism does not require evidence of efficacy or even safety.