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Bacteria Microscopic organisms that have a simple, one-celled structure and live in a variety of environments, including water, soil, plants and living bodies. There are billions of bacteria living naturally in the human digestive system—some beneficial and some potentially disease-causing.
CFU or CFUs An acronym for Colony Forming Units, the scientific term for “number of organisms” (i.e., how many microbes are in the colony of microbes in the product, or in your intestine). While there is no scientific standard for the number of CFUs required to be “probiotic,” the legitimate, science-based research studies we’ve seen all use quantities in the billions.
Clinical Trials While one may find quite a number of clinical trials using probiotics, very few seem to have anything to do with frequency, consistency or predictability of bowel movements. Effective consumption levels vary for strains as well as products; recommendations must be based on human studies on specific products.
Colonor Large Intestine A muscular, tube-like organ, approximately five feet long, that is part of the digestive system. It was long believed that its only function is to extract water from food and store waste until elimination. But experts now believe that the colon plays a part in the regulation of intestinal well-being, particularly through its complex bacterial microflora and maintenance of intestinal equilibrium.
Culture A colony of living microorganisms (e.g. bacteria), grown by humans for a specific purpose.
Fermentation A type of chemical reaction that converts complex organic substances to simpler ones. When certain live cultures are added to milk, they cause it to undergo fermentation. This is how buttermilk, crème fraîche, cultured butter, sour cream and yogurt are made.
Fiber Dietary fiber is a carbohydrate component of fruits and vegetables. Its chemical structure prevents it from being digested by humans. Since it cannot be metabolized to glucose, it contributes no calories to our diet. Instead of being broken down and absorbed, it passes through the colon, where it helps keep stool soft.
FOS, fructo-oligosaccharides, is a group of compounds related to, but not identical to, inulin. Sometimes the terms are used interchangeably, but there is a difference.
Friendly Bacteria & Yeast
Each individual has a unique population of microbes: There is no one “natural balance” common to every digestive system.
Friendly bacteria in humans include Lactobacillus, Bifidobacterium, Streptococcus and Saccharomyces. Saccharomyces boulardii, a commonly-used probiotic, is a yeast that is a strain of Saccharomyces cerevisiae. It is important to note that research on ideal levels of friendly microbes within the intestinal tract has not yet been published, so there can be no certainty as to how many “friendly” microorganisms are needed to be beneficial. Nor is every “friendly microbe” going to have probiotic benefits. Some experts do not consider L. bulgaricus and S. thermophilus to be probiotic, for example.
In addition, every person has a unique combination within his or her intestinal tract. Thus, a combination of strains that are helpful to one person may not work for the next person with the same condition.
A class of carbohydrates made up of chains of fructose molecules. The prebiotic inulin is a fructan.
Functional Foods & Beverages Foods that serve a helpful effect on the body beyond normal satiation and nutrition. There are actually two kinds of functional foods. The first is naturally-occurring foods, e.g. cranberries, which help with urinary tract health; cruciferous vegetables (broccoli, cauliflower, Brussels sprouts, cabbage, etc.), which contain elements which may increase activity of enzymes that help to detoxify carcinogens. The second is modified foods, where an added ingredient imparts the functionality. Examples include calcium added to orange juice or water for bone strength, or electrolytes and minerals added to flavored beverages to create “sports drinks” that help the body re-hydrate more quickly.
Intestinal Microflora The billions of tiny organisms that live naturally within the digestive tract.
A prebiotic fiber that nourishes or helps to stimulate the growth of probiotics. Inulin is perhaps the best-known prebiotic. It is
a naturally-occurring fructan. Inulin occurs naturally in thousands of edible plants, including asparagus, artichokes, bananas, barley, chicory, garlic, rye and wheat.
The abbreviation for Lactobacillus, a family of bacteria. Lactobacillus acidophilus (L. acidophilus) is the most commonly used probiotic bacteria. Lactobacillus bulgaricus (L. bulgaricus) and Lactobacillus casei (L. casei) are other commonly-used strains.
Live, Active Cultures All cultured products begin with live, active cultures: The microorganisms are alive and working (e.g., their primary work is to culture the milk). Subsequently, the heat used in the production of many products kills off the bacteria, or renders them inactive. Thus, any yogurt, for example, is made with “active cultures”—if the cultures were not active, they would not turn the milk into yogurt. However, they may not survive the production process to have any human benefit. Thus, a claim that says, “made with live cultures” implies zero probiotic benefits. It does not say that the cultures are still alive. Similarly, “contains live cultures” does not mean that they are active. If you are seeking a probiotic benefit, you need “live and active cultures.”
Microbe A microorganism.
Microorganism A general term for simple, one-celled organisms like bacteria.
NYA Live & Active Cultures Seal
Some yogurt products are heat-treated after fermentation, which kills most of the beneficial active cultures. The National Yogurt Association (NYA) has developed a Live & Active Cultures seal to help consumers identify refrigerated and frozen yogurt products that contain significant amounts of live and active cultures. Since use of the seal program is voluntary, some yogurt products may have the requisite live cultures but not carry the seal. The amounts refer to starter bacteria, are not necessarily at probiotic levels, and the NYA does not use the term “probiotic.” The seal is available to all manufacturers of refrigerated yogurt whose products contain at least 100 million cultures per gram at the time of manufacture, and whose frozen yogurt contains at least 10 million cultures per gram at the time of manufacture. However, there is no control over the number of live cultures inside when you purchase the product,
because once the product leaves the manufacturer, there’s no way to control if retailers and consumers keep the products at the right temperature, which is required to keep the cultures alive.
Oligosaccharide & Oligofructose
A short chain of sugars (usually less than 60 linked sugar molecules). Oligofructose is an oligosaccharide consisting of fructose molecules.
Prebiotic Prebiotics are a food source for probiotic bacteria, to make them more effective. Some prebiotics have been shown to enhance the absorption of important minerals like calcium. They can take the form of items commonly added to foods, such as dietary fiber.
Probiotic Literally, probiotic means “for life.” 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), which define probiotics as “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 (see Friendly Bacteria, above), but note that not all live, non-pathenogenic microorganisms are probiotics.
It is important to note that to date, the term “adequate amounts” of live microbes has not been defined by any official body or research authority.* No general guidelines for type, quantity, or delivery system of probiotics that would restore regularity have ever been established, nor is there evidence that a mix of strains are inherently better at this than is any single strain. As an indication of what might net out, current, credible research uses CFUs of a billion or more. But, we can’t state it emphatically enough, as with “antioxidants,” another item that has high consumer interest but has not been quantified: While probiotics do help human health in some way, no one knows enough about either yet, to be able to state definitively what quantities or types are necessary to help maintain health or address disease. And neither antioxidants nor probiotics will cure bad dietary habits.
*According to Dr. Mary Ellen Sanders, a probiotics expert, as of this writing, in May 2008, “The only exception I know of is that I believe there is a standard in California, and possibly Oregon, that stipulates if you are going to make ‘acidophilus milk,’ you have to have 10e6/ml of the L. acidophilus in the milk.”
The abbreviation for Streptococcus, a family of bacteria used as a probiotic. Streptococcus Thermophilus (S. Thermophilus) is a frequently-used strain.
The bacteria in the culture used to start a fermented product—cheese, kombucha, sour cream, yogurt, etc. The term references both the particular strains of bacteria and the numbers of bacteria required. The number of bacteria required by the National Yogurt Association’s Live & Active Cultures definition, for example, refers to the amount of bacteria in the starter culture, not in the finished product.
The combined beneficial effects of probiotics and prebiotics. For example, yogurts that contain live, active cultures as well as the prebiotic inulin produce a synbiotic effect. Synbiotics also refer to nutritional supplements containing probiotics and prebiotics.