September 21, 2008
Probiotics and Your Health
By Unal, Robert R
Probiotics and their associated health benefits, have been internationally known and consumed for decades. However, it is only in recent times Americans have begun to embrace the bacteria culture. In only a matter of a couple years, the number of commercially available products, probiotic and prebiotic, has grown exponentially. The first probiotic product was based on Eastern philosophy and a proactive approach to health. In the 1930s, a medical microbiologist in Japan successfully cultured a probiotic strain and packaged it in efforts to prevent illness and death caused by poor nutrition and infectious disease. It was given the name "Yakult," the word for "yogurt" in the proposed universal language of Esperanto. That language never took hold, but Yakult did. Yakult was delivered door to door and paved the way for a new type of product.
Today the North American probiotics market, which earned $698 million in 2006, is expected to reach $1.7 billion by 2013. But to fully realize the potential for probiotics, one must grasp the science behind it.
What are probiotics?
The word "probiotic" comes from the Greek meaning "for life." The World Health Organization (WHO) and the Food and Agriculture Organization of the United Nations (FAO) in a joint 2001 report described probiotics as "live microorganisms, which, when administered in adequate amounts, confer a health benefit on the host."
Probiotics are typically small living bacteria that can colonize in the gastrointestinal tract. Their habitation helps to maintain a healthy gut, among myriad health benefits still not fully realized. Humans have trillions of bacteria in the intestinal tract; some good, some bad, though roughly 70 percent are considered neutral. Scientists have learned that the ratio of these bacteria in the gut, particularly good vs. bad, play an important role in health and well- being. When there are favorable numbers of good bacteria present, it is more likely that the individual will experience less illness and discomfort.
Probiotics vs. yogurt
Probiotic products are sold in the form of dietary supplements and food, though dairy is an ideal delivery vehicle because of similar storing requirements. It is important to note that Yakult, the world's first probiotic dairy beverage, is by no means "yogurt." Most yogurt may contain live bacteria that may be good for you, such as Streptococcus thermophilus and Lactobacillus bulgaricus, however they cannot withstand the high acidity of the stomach in order to enter the intestines alive and active. Science has shown that the benefits of good bacteria are primarily gained in the intestines, which is one of the defining criteria between yogurt and probiotic cultures.
Health benefits of probiotics
The health benefits of probiotics vary, depending on the strain. "It's so tempting to talk about probiotics as if they were one thing," says Mary Ellen Sanders, executive director of the International Scientific Association for Probiotics and Prebiotics. "You can't just generalize that because one probiotic does one thing, they'll all do it."
This is because each strain is different and therefore has its own unique effect on the body. The process for understanding all of the associated health benefits of a bacterium requires multiple clinical trials. There are hundreds of different types of probiotics; some have been studied, others have merely been identified - thus, there is much needed work to be done.
One of the most studied probiotic strains in the world and the one exclusive to Yakult is Lactobacillus casei Shirota. Research began nearly 80 years ago in Japan and is still being conducted around the world, due to the promising results. For example, one study showed the positive effect on the immune system's natural killer cells - the cells that protect the body from pathogens and disease (Takeda and Okumura, 2007). Another study indicated that L. casei Shirota improves gastrointestinal symptoms in people with chronic constipation (Koebnick et al., 2003).
It is important to note that health claims cannot be made for commercial probiotic products without scientific evidence. Currently there are no approved health claims for probiotics in the United States for food or dietary supplements. Probiotics are not assured to cure, prevent or treat any disease, even though there are promising human clinical trials.
Today, many probiotic products on the market may claim a wide variety of health benefits despite the lack of significant scientific evidence. There is also not enough information regarding probiotics stability since processing conditions may cause cell injury and loss of viability. Appropriate labeling should state the genus, species, strain of probiotics and viable concentration present in the product and storage conditions.
Safety of probiotics
The long history of safe use of probiotic bacteria is an excellent substantiation for the safety of probiotic products. Probiotic cultures have been consumed in large quantities through fermented foods for centuries, and are naturally found in human intestines. Comprehensive review of safety records on probiotics and epidemiological reports on the safety of dairy-based fermented foods suggest no evidence of pathogenic or virulence properties of probiotics concerned with human infections.
Accordingly, careful evaluation of the safety and the effectiveness of all new species and strains of probiotics before incorporating them into foods are needed by food companies. The FAO/ WHO Expert Consultation Report (2001) suggests that probiotic strains should be evaluated for a number of parameters, including antibiotic susceptibility, toxin production, metabolic and haemolytic activities, infectivity in immune-compromised animal models, and adverse symptoms in humans.
The future of probiotics
There is scientific proof that particular strains of probiotic cultures confer benefits to the host health and are safe for human consumption. These cannot be extrapolated to other strains, as such effects are strain-specific.
Further clinical studies are required before credibility is given to health claims regarding the use of probiotic products in healthy individuals. Worldwide uniform regulatory procedures for probiotic foods are required to guarantee appropriate labeling, manufacturing and handling procedures, as well as the health claims made for products.
The future success of probiotics is very promising and undoubtedly depends on an extensive multidisciplinary joint effort (food scientists, medical scientists, nutritionists, dietitians and consumer health experts). Currently, the biggest challenge for probiotics is to establish scientific proof in humans showing clinical efficacy, mechanisms of action, dosage, duration of use and safety parameters throughout a randomized, double-blind, placebo- controlled clinical trials through multidisciplinary joint effort. It can be expected that probiotics will make a significant impact on the U.S. market because of their advantages in terms of price, safety and greater accessibility to a large number of people. It is then up to the customer to decide which probiotic works best for them.
Robert Unal is Science Manager at Yakult U.S.A. Inc., Torrance, Calif. He has more than 10 years of experience in food safety and microbiology. Prior to joining Yakult U.S.A., Unal was a consultant with probiotics company ProbioHealth, and director of food microbiology with immunodiagnostics company BioCentrex.
Copyright BNP Media Jul 2008
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