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About Probiotics

What are probiotics?

The Food & Agriculture Organization (FAO) of the United Nations and the World Health Organization (WHO) defined probiotics and the uses of probiotics in the report of a Joint FAO/WHO Expert Consultation on Evaluation of Health and Nutritional Properties of Probiotics in Food, including Powder Milk with Live Lactic Acid Bacteria, 2001.

This report can be found at:
http://www.who.int link

'The works of Metchnikoff and Tissier were the first to make scientific suggestions about the probiotic use of bacteria, even if the word "probiotic" was not coined until 1960, to name substances produced by microorganisms which promoted the growth of other microorganisms (Lilly and Stillwell, 1965). Fuller (1989), in order to point out the microbial nature of probiotics, redefined the word as "a live microbial feed supplement which beneficially affects the host animal by improving its intestinal balance." A quite similar definition was proposed


by Havenaar and Huis in Veld (1992): "a viable mono or mixed culture of bacteria which, when applied to animal or man, beneficially affects the host by improving the properties of the indigenous flora." A more recent, but probably not the last, probiotic definition is "live microorganisms, which when consumed in adequate amounts, confer a health effect on the host" (Guarner and Schaafsma, 1998). It is clear that these definitions have:

There have been hundreds of published studies on probiotics in the last 15 years. Each year the amount of data continues to grow. A search conducted on the top probiotics showed over 1300 publications in November 2011.

How do probiotic bacteria get their names?

Like animals and humans, bacteria have family names too. They are referred to as genus, species and strain type. One example which many people know is Lactobacilli, the lactic acid bacteria which are found in many probiotics.

Lactobacilli belong to the Lactobacillaceae "family".

There are many members of this family, so we next look for the genus (which is like a last name). A genus of the Lactobacillaceae family is Lactobacillus. We then look for the species (which is like a first name). A species of Lactobacillus is acidophilus.

The strain further identifies the exact family member (such as 1st in Queen Elizabeth the 1st in royalty, or Junior in families). The strain is usually a combination of numbers and letters. In Table 1, 123SAG is from the family Lactobacillaceae, the genus is Lactobacillus, species is acidophilus and the strain is 123SAG, so the full name of the bacteria is actually Lactobacillus acidophilus 123SAG.

Many probiotics are not clinically tested, but instead use the data from other more specific strains to apply to their probiotic. One cannot apply the specific strain study data to all products containing that genus or species, only that strain. Therefore, not all probiotics (strains) are the same.


Table 1.
Bacterial Family Tree

VSL#3 chart

Bacterial Strains

VSL#3® is a high potency probiotic preparation containing the following strains:

*VSL Pharmaceuticals consider the strain number proprietary that is why we have not put the strain name (numbers) next to each of our bacteria.

Not all probiotics are the same, and the specific activity and efficacy of a probiotic is strongly linked to the bacterial strains that are present.

For each bacterium, you need to consider:


Genus Comparison

Each genus, each species and each strain has different characteristics and different functions, like the dogs below, where the genus and species also have different characteristics and functions!

VSL#3 chart

Are all probiotics the same?

Not many probiotics have had the specific strains contained in their products studied, either clinically or in the laboratory setting.

Richard N Fedorak, a leading Canadian researcher in Alberta, Canada was interviewed by Gastroenterology & Hepatology journal, on probiotics for the management of UC (Ulcerative colitis):

Different probiotic preparations have very different methods of growth, harvest and storage.

Developing bacterial cells, maintaining bacterial count and ensuring the correct number of bacterial concentrations is not easy. Therefore, the well manufactured probiotics are usually manufactured to a higher level and guarantee a high bacteria count (in the hundreds of billions of cells).

The microorganisms/bacteria should be alive.

The probiotic bacteria must be able to survive the journey through the entire GI tract to reach the colon, where the highest microorganism activity occurs.

Further reading:

link 1 | link 2

Probiotic facts

Probiotics contain bacteria that are normally present in a healthy digestive tract.

Probiotic products should contain live microorganisms thought to be beneficial to the body.

Most probiotics are dietary supplements.

VSL#3 is a probiotic medical food.

Increasing evidence shows that the activity of probiotic bacteria in the human GI tract plays a role in the dietary management of certain diseases.

Further reading:

link 1 | link 2 | link 3 | link 4 | link 5 | link 6