Whole Living Guide >Investigation

Culture Club: Probiotics for the Consumer
By Corinna Richards . Illustrations by Jim Bliss

The intestinal tract is home to thriving colonies of over 400 types of microorganisms known collectively as intestinal microflora. While some are responsible for causing disorders such as irritable bowel syndrome, allergies, and digestive problems, others are working hard to combat pathogens and help the body release toxins, and thus keep the immune system healthy. Beneficial microorganisms that normally inhabit the human colon become established shortly after birth and remain relatively stable throughout life, depending on one’s diet and the amount of de-stabilizing pathogens.

Today, living cultures of beneficial gastrointestinal microflora, called probiotics, are available as supplements to re-stabilize or boost the gastrointestinal ecosystem.
If you were aware of probiotics 25 years ago, choosing which products to purchase would have been easy. There were only three or four on the American market and they were costly. But by the early 1980s several new products had emerged. Among them were liquid and powder forms of the bacterium Lactobacillus acidophilus, including the first non-dairy L. acidophilus product. By the mid-1980s numerous other probiotic supplements had been introduced, including other species of Lactobacillus such as L. rhamnosus and L. bulgaricus.

Research continues to examine the effects of beneficial microorganisms—generally bacteria but also yeasts and fungi. Add to that the fact that consumers are becoming more aware of the important role the body’s natural processes play in preventing and combating disease, and the result is a market flooded with microflora supplements. Each is packaged differently, claims different benefits, and contains different strains, quantities, and combinations of live probiotic microorganisms. Their cost varies widely as well. Given all this, it can be difficult to look beyond the hype and choose a product that is safe and effective.

beneficial bacteria
Many health practitioners agree that there are key factors to consider before choosing a probiotic. Dr. Barry Golden, PhD., of the Department of Family Medicine and Community, Tufts University School of Medicine, advises, “Only buy probiotics that have a stated dose, list the probiotic, and have an expiration date.” Dr. Golden also recommends checking the scientifically proven health benefits of the specific probiotic ingredients. Manufacturers should be able to provide any information that is not presented on the product label, such as the genus, species, and strain of the probiotic contents. They should also be able to supply details of research conducted on both animals and humans.

The available strains have been isolated from many different sources. These include human, animal, and plant varieties as well as some that have been extracted from soil (sbos). According to nutritionist Brenda Lynn Pretesch, supervisor of Research and Development for Wakunaga of America Co., strains derived from human sources adapt better to the human intestinal tract.

To do their job effectively, the live organisms must attach themselves to the intestinal lining, rather like Velcro. Though their colonization is not permanent, if they are unable to fix themselves at least temporarily, they will simply pass out of the system without taking effect. Human-derived probiotics are more likely to colonize the intestinal tract. Another factor to consider is that most additional intestinal microflora, whatever their origin, do not colonize for long. This is one reason why high numbers of viable organisms are important. It also means that probiotics may need to be taken on a regular, if not long-term, basis.

therapeutic strains of probiotics
While the most trusted and well-researched types of probiotic organisms belong to one of two genera, Lactobacillus and Bifidobacterium, each has a series of species which inhabit specific areas of the intestinal tract or upper GI system and manage their environments differently. One of the most common species of probiotic bacteria is Lactobacillus acidophilus; there are already several variants that are being incorporated into different dietary supplements, though not all are equally effective.

Though a healthful diet does help maintain colonies of friendly microflora, many of the habits of modern lifestyles can compromise the natural balance of the ecosystem within the gastrointestinal tract. One such threat is the overuse of antibiotics. Studies have shown that while antibiotics destroy pathogenic bacteria, they can also kill beneficial organisms and may upset the balance of the digestive system, causing diarrhea or allergic reactions. A course of probiotics can be used simultaneously with, and for several weeks after, a course of antibiotics to prevent this. Lactobacillus acidophilus DDS-1 has been reported to be highly resistant to commonly prescribed antibiotics such as penicillin, streptomycin, and aureomycin.

Another potential negative side effect of both antibiotic overuse and our modern-day, sugar-laden diets is candidiasis, an overgrowth of yeast. This type of infection is also common among people whose immune systems are compromised by diseases such as AIDS or diabetes. The microorganism L. acidophilus, which resides naturally in the mouth, vagina, and small and large intestines, can be supplemented to treat or prevent Candidiasis. It protects the body from invaders such as candida albicans by producing natural antibiotics and can help restore the body’s natural balance.
An unhealthy diet can also be responsible for disorders such as heart disease and high cholesterol levels. Studies have shown that cholesterol reduction can be enhanced by probiotic supplements. Lactobacillus plantarum variant OM has been shown to preserve nutrients such as omega-3 fatty acids, and also to increase their content. Its other unique ability is to speed up the breakdown of protein; this makes it a healthful aid to digestion.

Lactobacillus reuteri produces a substance named reuterin, which prevents harmful bacteria from colonizing the intestine. It also binds the mucus lining of the stomach, reducing the risk of gastric disorders such as leaky-gut syndrome, and increases the effectiveness of the immune system.
A relatively new Lactobacillus species is L. salivarius, which requires a special culturing process. Flourishing in the small intestine, it doubles its population every 20 minutes. L. salivarius has another very special talent—it can survive and grow in both anaerobic (without oxygen) and aerobic (with oxygen) environments. This gives it a distinct advantage over L. acidophilus, which has little or no growth in aerobic conditions. It can also break down undigested protein. This means that it helps the body eliminate toxins produced during digestion. Further, L. salivarius has been shown to destroy Heliobacter pylori, the leading cause of ulcers.
Some strains of probiotics are more transient than others, colonizing the intestinal tract for only one to three days. Lactobacillus rhamnosus GG is one of these. It has been studied extensively in adults and children and has been shown to improve travelers’ diarrhea, antibiotic-associated diarrhea, and colitis. This friendly microorganism works to boost the immune system by releasing toxins.

Another transient strain is Lactobacillus bulgaricus, which is found in yogurt and cottage cheese. During its residency L. bulgaricus helps to increase the environmental acidity levels to inhibit harmful bacteria. It also gives the immune system a boost. Allan Walker, md, Professor of Pediatrics at Harvard Medical School, claims that studies have shown that introducing it into children’s diets can reduce their chances of contracting allergic diseases, such as lactose intolerance, asthma, eczema, and rhinitis, by up to 50 percent.

Bifidobacteria bifidum, the major bacterial component of the human large intestine, is also found in the small intestine and vagina. It works to increase intestinal acidity, making a less hospitable environment for harmful bacteria. It also competes with and controls populations of pathogenic bacteria and yeasts. This microorganism is also effective in combating candida albicans and is responsible for producing essential B vitamins.

Sources of Probiotics

If you’ve decided you want to add a little live culture to your gastrointestinal ecosystem, you need to know where to find it. You have two options: probiotic food sources or supplements. In the American market, probiotic food sources consist almost exclusively of yogurts and cottage cheese. Probiotic bacteria used in these products include Lactobacillus acidophilus and Streptococcus thermophilus. However, because these strains have a shorter life span, some products may no longer contain live bacteria or only very small amounts by the time you eat them. The estimated shelf life and species of probiotic bacteria included in these “living foods” is usually shown on the label, though the specific strain and potency of viable organisms is not shown and is usually somewhat lower than in dried supplements. Some health stores stock non-dairy acidophilus liquids and juices; similarly these “living liquids” contain smaller amounts than do concentrated supplements, and also require constant refrigeration. Fresh sauerkraut, sometimes available in the supermarket’s refrigerated section, also contains these beneficial microorganisms. However, not everyone wants to consume large quantities of yogurt and sauerkraut on a daily basis.

The main advantage of a supplement is that the concentration of live microorganisms can be higher. Supplements are available in capsule form as well as in powders that may be added to cereal or cold drinks. The usual measurement for probiotics is in Colony Forming Units (CFUs). This refers to the number of live bacteria present in each serving. A typical capsule will contain at least 1.25 billion CFU. The average initial dosage will range from two to four capsules each day, being reduced after the first week or two. Though the product label should offer this information as well as stating how long the product should retain its stated potency, this measurement is only valid at the time of manufacture. There is no guarantee that it is still the case by the time of purchase.
To be certain that your supplement is alive and kicking, try a simple test at home. Take two to three times the recommended amount. If within a few hours you are experiencing temporary bloating and flatulence, you can rest assured that your new colonies of probiotic organisms have taken residence and are cleansing your gastrointestinal system.

Within a few days of using probiotics you may already notice relief from minor symptoms or less digestive discomfort. For more severe symptoms, the effect will vary depending on the strength of your dosage, but relief has been reported within two weeks.

direct delivery systems
Several combination formulas have been developed for broad-spectrum use in the treatment for disorders such as candidiasis, parasitic infection, and irritable bowel syndrome. With such a range of probiotics available, you might think that your best bet is to take a combination or a multiple strain dosage of live organisms; however, this may not always be the best choice.

Most health practitioners recommend supplements containing single strain cultures. Each strain of friendly microflora has its natural place of residence within the gastrointestinal system. To work effectively they must reach their destination intact. Secretions of stomach acid can kill beneficial microflora before they reach home. To prevent probiotic bacteria from being wiped out before they reach their destination, some manufacturers take important precautions. After being isolated from their original source, beneficial bacteria are then grown in a selected nourishing medium. That medium, or supernatant, also acts as a buffer to shield the viable microorganisms from gastric juices and should not be extracted from the end probiotics product.

Taking probiotic supplements with meals or shortly after can also ensure their safe passage. As you eat, stomach acid is neutralized when its contents combine with alkaline secretions in the small intestine. This reduces the risk that microorganisms will be killed by acid secretions. Also, avoid taking probiotics with acidic fruit juices. Some probiotic supplements use an encapsulation delivery system, in which bacteria intended to reach the intestine are combined with vitamin E and wheat germ oil. The oil matrix does not get broken down in the stomach and so the probiotic strains are able to survive the gastric juices and reach their destination intact. Lipid-dissolving secretions in the intestine then remove the protective oil layer.

It has been argued that a combined strain of probiotics creates conflict between strains rather than helping promote a healthy environment. This is not actually the case, as the diverse species of probiotics are not likely to interact at all, since each microorganism will seek its own best environment.

Many specialists in enzyme nutrition advise that combination probiotics should not be overused as they may cause cramping, bloating, and other minor discomforts.

the future of probiotics
Companies and independent researchers in the us, Canada, and Europe are involved in studying the effects of probiotics and developing new strains. Some specific areas currently being studied in more depth include allergy treatment, probiotic adhesion to the intestinal wall, and cancer prevention. Manufacturers are also working to improve storage by developing more heat-resistant forms of probiotics that do not need to be refrigerated and developers are also examining better methods of processing and packaging.

With the help of probiotics, the future of our microbiological ecosystem is looking healthy.