Probiotics - bacteria for life !

What Are Probiotics ?


It may come as a surprise, but not all bacteria are bad for you. It’s common to hear news reports about harmful bacteria (pathogens) these days, and most of us are familiar with some of their names-Listeria moncytogenes, Clostridium botulinum and various strains of Salmonella, for instance. But other families of bacteria are not injurious to human health, and may, in fact, provide some health benefits, particularly those in the Lactobacillus and Bifidobacterium genera. Probiotic means “for life.” The definition of a probiotic has changed over time, but these days, the generally accepted definition is the one issued by the Food and Agricultural Organization (FAO) of the United Nations and the World Health Organization (WHO). Probiotics are “live microorganisms which when administered in adequate amounts, confer a beneficial health effect on the host.” These microorganisms do not promote or cause disease. They comprise multiple species and subspecies of bacteria, as well as one species of yeast, Saccharomyces, but note that not all live, non-pathenogenic microorganisms are probiotics.


Probiotics are just beginning to catch on in the U.S., but they’ve been a bigger deal in Europe and Asia for years. For instance, Dannon’s Activia, a recent introduction in the U.S., has been sold overseas since 1987. Considering that people of other nations tend to turn to foods and natural remedies for good health, while Americans rely far more heavily on pills and medications, this is not surprising. In fact, according to the International Probiotics Association, Japanese grocery store shelves are stocked with dozens of probiotic-containing foods, while in Europe, yogurts and fermented milks are the most widely-consumed probiotic products. In the U.S., consumption of probiotic supplements far outweighs consumption of foods containing these beneficial bacteria.

Due to the vast number of cells involved in probiotics, counts for these bacteria in any product tend to be very high, often numbering in the billions. While many foods containing probiotics do not list specific bacterial counts, it isn’t uncommon to see numbers of five to ten billion associated with a single serving of probiotic-containing foods. In general, numbers of probiotic bacteria are expressed as a CFU count.


CFU stands for “colony forming unit.” A CFU is a viable cell. Viable cells are live cells that have been rendered dormant and must be reactivated after ingestion on their journey toward the intestinal tract. Consumers are likely to find viable cells in freeze-dried powders that might be in probiotic capsule supplements, for example; live cells are often found in probiotic-containing dairy foods.


You may also see the terms “prebiotics” and “synbiotics.”

Prebiotics are indigestible ingredients in foods that are thought to assist the growth and/or activity of certain probiotics, especially those in the bifidobacteria family. Two of the more commonly-found prebiotics are inulin and fructo-oligosaccharides (FOS).

Synbiotics are supplements or functional foods that contain both a prebiotic and a probiotic (a functional food is one that may provide a health benefit beyond basic nutrition; the concept is based on the ancient Hippocratic concept of food as medicine). The thought is that there are certain combinations of prebiotics and probiotics that can work together especially well.


Neither prebiotics nor synbiotics is covered in this article.