PREBIOTICS, PROBIOTICS and SYNBIOTICS NEW OR OLD CONCEPT?

Chia sẻ: Nguyen Uyen | Ngày: | Loại File: PDF | Số trang:13

Thêm vào BST

Báo xấu

118
lượt xem 34
download

Download Vui lòng tải xuống để xem tài liệu đầy đủ

Although the concept of prebiotics and probiotics started in the 1970’s, it was dormant until 1994 when Danone, an European dairy and confectionary manufacturer, launched Actimel probiotic drinking yogurt in 100 ml daily-dose bottles. Actimel revolutionizes the dietary supplements market and is now considered as the leading “immunity” yogurt brand worldwide. Actimel earned over $1.8 billion in retail sales in 2007. The concept of prebiotics and probiotics reached its peak in April 2008 when the International Probiotics Association had its World Congress in Los Angeles, CA. ...

Chủ đề:

Bình luận(0) Đăng nhập để gửi bình luận!

Lưu

Nội dung Text: PREBIOTICS, PROBIOTICS and SYNBIOTICS NEW OR OLD CONCEPT?

PREBIOTICS, PROBIOTICS and SYNBIOTICS NEW OR OLD CONCEPT? Although the concept of prebiotics and probiotics started in the 1970’s, it was dormant until 1994 when Danone, an European dairy and confectionary manufacturer, launched Actimel probiotic drinking yogurt in 100 ml daily-dose bottles. Actimel revolutionizes the dietary supplements market and is now considered as the leading “immunity” yogurt brand worldwide. Actimel earned over $1.8 billion in retail sales in 2007. The concept of prebiotics and probiotics reached its peak in April 2008 when the International Probiotics Association had its World Congress in Los Angeles, CA. It was the first global prebiotics and probiotics event attended by industry, academia and health care representatives. A world congress on nutrients that were ignored or unheard of just 10 years ago. Worldwide, prebiotics, probiotics and synbiotics are gaining popularity and their claimed beneficial health effects are now accepted and trusted by the general population. Daily intake of these supplements (i.e., drinking yogurt) is now fashionable among affluent families and young
generation. Consequently, these dietary supplements are now deliberately added to many products with claims attesting to their health benefits. So, is daily supplementation with prebiotics, probiotics or synbiotics a truly new and innovative concept? Definition of prebiotics, probiotics and synbiotics Probiotics are living microorganisms, which, when ingested or locally applied in sufficient numbers, provide the consumer with one or more proven health benefits. The probiotic strains most commonly used are Lactobacillus sp. (e.g., rhamnosus, acidophilus, casei, plantarum, reuteri, etc.), Bacillus breve, Bifidobacteria sp. (e.g., lactis, longum, etc.), lactococcus lactis and Propionibacterium freudenreichii. The term “prebiotic” was coined by Gibson and Roberfroid in 1995 to describe ingredients that can boost the growth of beneficial bacteria (probiotics) in the gastrointestinal (GI) tract. Prebiotics are derived from insoluble fibers and oligosaccharides and include inulin (beta (2,1) linear fructans), xylooligosaccharides, lactulose, galactooligosaccharides and fructooligosaccharides. Prebiotics are thus non-digestible food ingredients that, when consumed in sufficient amounts, selectively stimulate the growth and/or activity of one or a limited number of bacteria in the GI tract resulting
in documented health benefits. The most well known prebiotic is inulin, which is the major polysaccharide in many subsurface tubers and bulbs like onions and agave. Agave is a plant in Arizona and is used extensively in the production of tequila (a Mexican hard liquor). Synbiotic is a mixture of pro- and prebiotics, which beneficially affects the host by providing the survival and implantation of selected live microorganisms in the GI tract. The market for prebiotics, probiotics or “healthy” bacteria and synbiotics continues to grow as awareness of their health benefits increases. Nowadays, even some manufacturers are promoting the prebiotic effects as more useful than the probiotic bacteria that they feed. Claimed Health Benefits - Prebiotics Claimed benefits of prebiotics include improved health and immunity, reduced formation of potentially toxic or carcinogenic compounds (De Preter et al., 2008), enhanced survival and reduced infections. The potential of inulin to support bone health and prevent osteoporosis, which affects over 70 millions people in the US, Europe and Japan, is gaining popularity. Currently, two approaches are being pursued to prevent osteoporosis. The first approach is to optimize bone mass acquisition during adolescence and
the second approach is to minimize bone loss after menopause. The prebiotic inulin works through the first approach by increasing colonic calcium absorption during adolescence. In a study with human adolescents, supplementation with a mixture of oligofructose and inulin is reported to result in a higher absorption of calcium (38%) than the placebo group (32%) (Abrams, 2005). The second approach is that of medications used for the prevention and/or treatment of osteoporosis (e.g., Fosamax, Boniva, Evita, etc.). These medications target the dynamic nature of bones by reducing the rate of bone breakdown or loss. By reducing bone loss, bones can accumulate bone minerals and increase bone density. Researchers from Baylor College of Medicine recently discussed their findings in the Journal of Pediatrics, indicating that a daily supplement of prebiotics inulin and oligofructose may help adolescents maintain an appropriate body weight and body mass index (BMI) during pubertal growth. BMI normally increases during puberty and adolescents supplemented with prebiotics for one year had a normal BMI of 0.7 kg per m2 compared to the control group with a BMI of 1.2 kg per m2. The researchers postulated that inulin and oligofructose may regulate appetite by increasing GI peptides that modulate satiety such as glucagon-like peptide-
1(GLP-1) and concluded that prebiotics may prevent excessive teenage weight gain. The potential benefits of prebiotics for infant health have also gained increasing acceptance by parents. Infants fed formula contained prebiotics had a 6.5% lower incidence of recurring respiratory infections than placebo- fed infants, according to a report by European researchers (Arslanoglu et al., 2007). The authors indicated that while the exact mechanism of action is not known, the immune modulating effect of the prebiotics via modification of the intestinal flora was the likely reason. The study adds to an ever-growing body of research reporting benefits of the inclusion of prebiotics in infant formula. As we age, the microbial flora of the intestinal tract changes with decreases in levels of the beneficial bifidobacteria and increases in potentially harmful clostridia, streptococci and enterobacteria. The shift in the intestinal flora may be the etiology of constipation, colitis, irritable bowel disease, or colon cancer in the elderly. Prebiotics can normalize the intestinal flora as substantiated by studies conducted at Providence University in Taiwan (Chung et al., 2008). The study consisted of elderly subjects (average age of 78.6) who were fed either a daily supplement of
xylooligosaccharides (prebiotics from bamboo) or sucrose (placebo control). At the end of the 4-week study, the population of the beneficial bifidobacteria in the supplementation group was increased by 35% while no increases were noted in the placebo control group. Since bifidobacteria species seem to play a key role in the digestive and natural immune functions of the GI tract, the beneficial alterations on bifidobacteria population induced by prebiotics do contribute to the overall health and well-being of elderly people. Claimed Health Benefits – Probiotics and Synbiotics Probiotic strains can be applied to a number of dairy products such as yogurt, cream cheese, buttermilk, ice cream and fruit juices. Foods containing probiotics are almost exclusively refrigerated products since probiotics are destroyed by heat and other processing conditions. Claimed benefits of probiotics include immune stimulation, enhancement of bowel mobility, reduction of inflammatory or allergic reactions. Apparently a combination of different probiotic strains is more effective than single strains in reducing the ability of potentially pathogenic bacteria to colonize the GI tract (Collado et al., 2007). The beneficial effects on the GI tract are
related to the capability of the probiotic bacteria to adhere to the GI walls and, hence, displace the pathogenic enterobacteria. In a study published in an open-access journal, Pant and co-workers (2007) demonstrated that supplements of Lactobacillus rhamnosus GG probiotic bacteria are effective against GI infection and diarrhea in infants. Probiotics administered prior to infection with rotavirus can even prevent rotaviral diarrhea. The proposed mechanism of action is the ability of probiotics to cause stabilization of the mucosal barrier, production of anti- microbial compounds and stimulation of the mucosal immune response leading to an increase in secretory immunoglobulin A. Researchers at the University College London conducted a randomized clinical study with people diagnosed with alcoholic cirrhosis. The probiotic Lactobacillus casei Shirota was given as a supplement for four weeks. The authors reported that probiotics can restore the immune function of neutrophils thus offering benefits for alcoholic livers (Stadlbauer et al., 2008). The ability of the probiotic Lactobacillus salivarius to neutralize Listeria monocytogenes, an often-lethal pathogen in pregnant women is
related to the probiotic secretion of an antibiotic-like compound (Corr et al., 2007). Synbiotics have been shown to provide multiple advantages such as to reduce symptoms of childhood eczema (atopic dermatitis) and other allergic reactions in infants. According to the American Academy of Dermatologists, eczema affects between 10 to 20% of all infants, but almost half of these infants will be free of symptoms between the ages of 5 and 15. The incidence of colorectal cancer is rising and it is suggested that 80% of colorectal cancers may be preventable by dietary changes. In fact, daily intake of synbiotics can significantly decrease beta-glucuronidase activity, an enzyme produced by pathogenic bacteria in the GI tract (De Preter et al., 2008). Inhibition of bacterial beta-glucuronidase is valuable in the prevention of colon diseases. It has been shown that administration of synbiotics can reduce colon cancer markers and colonies of Clostridium perfringens, a strain reported to possess the metabolic capacity converting non harmful dietary ingredients into carcinogenic molecules. Regulatory Status
The market for prebiotics, probiotics and synbiotics will continue to grow and from a regulatory standpoint what claims can be made for those products? In the US, these products could be regulated as dietary supplements, GRAS (Generally Recognized As Safe) ingredients, food additives, or drugs depending how the product is claimed. In general, beneficia l health claims can be divided into nutritional claims, structural/functional claims and treatment claims, and each type of claims has its own burden of sufficient scientific evidence and substantiation. Most of the products already on the market are labe led with structural/functional claims, which describe the role of the nutrient or ingredient intended to affect normal structure of functions of the human body. Structural/functional claims do not require pre-market approval and authorization by the Food and Drug Administration (FDA), which means that the “burden of proof” rests with the manufacturers and not the FDA. As structural/functional claim, the manufacturers can label these products as (a) to support immune function, (b) to support healthy intestinal balance, (c) to promote immune system and overall health, (d) to fortify body natural defenses or (e) to maintain a healthy GI tract. Since the claim is not
approved and/or regulated by FDA, effectiveness of some products remains doubtful. A search of the FDA data base reveals that there are no approved treatment claims for prebiotics, probiotics or synbiotics. Treatment claims refer to the diagnosis, treatment, mitigation or prevention of a disease, disorder or abnormal physical state or symptoms. Beneficial health claim is not without risk and liability. Indeed, in January 2008 a class action was filed against the company Dannon, accusing it of fraudulent health claims to sell some of its Activia and DanActive yogurt brands. The lawsuit alleges that Dannon does not possess “clinically and scientifically” proven data to claim beneficial health effects. New or Old Concept? Archeological discoveries prove that early humans knew and included prebiotics in their diet as a caloric source. Subsurface tubers, rhizomes and perennial bulbs, many rich in prebiotics, were important sources of energy in prehistoric staples. Inulin, the major indigestible polysaccharide in many subsurface tubers and bulbs like onions and agave, dominated the dietary intake of humans hundreds of thousands of years ago. In fact, archeological
records showed residues of inulin-rich plants in pits used as earth ovens. By cooking the agave and other inulin-rich plants in earth ovens, where temperatures were less than 100o Celsius, the loss of inulin from the cooking process was minimized. Finally, To entice the health-conscious individuals, nutritionists claim that most consumers’ diets are fiber deficient. In response to this, the market for fiber-enriched foods and beverages and prebiotics has steadily grown. Then with obesity on the rise worldwide and the increased incidence of diabetes at all ages, weight-conscious consumers are seeking food products with less calories, reduced sugar, less fat and at the same time providing health and performance benefits. No wonder why probiotics and synbiotics are in great demand. So, is it a new and innovative concept? Perhaps only true to Westerners! For Vietnamese people, we are all aware of “dưa chua”, this fermented product dating back to who knows when. Jars of the fermented green mustard are a familiar sight in every Vietnamese’s kitchen and the proud displays of the Vietnamese ladies. “Dưa chua”, a milestone of “công dung ngôn hạnh”! “Dưa chua”, a synbiotic mixture of healthy probiotic
bacteria and prebiotic fibers in a slightly pungent, sweet and sour aqueous medium! Our mothers and sisters have known for years the benefits of probiotics (albeit cannot explain it) that to make excellent crunchy “dưa chua”, don’t use distilled or sterilized water but one must re-use the “nước dưa” from the previous batch. Traditionally, “nước ao” yields the tastiest “dưa chua”. That’s ingenious, that’s recycle and that’s sustainability! We don’t need to be told that prebiotics can prevent weight gain. Ask any Vietnamese female teenager, she will tell you how to lose weight with a diet based on “nước dưa chua”. “Dưa chua” is also our culture since there is no “Tết” without the traditional “thịt mỡ dưa hành câu đối đỏ” and “dưa chua” undoubtedly enriches our culinary repertoire with dishes like “thịt đông dưa chua”, “canh dưa chua nấu sườn” and “dưa chua xào thịt bò”. Our fathers don’t care whether bamboo contains xylooligosaccharides but they do appreciate “vịt xáo măng” and they do recognize the delicious and healthy effects of “măng”. We are also experts in probiotics. Look at the Vietnamese “ya ua”. I must honestly attest that no brands of yogurt can surpass our Vietnamese “ya-ua made with condensed milk” sold in transparent plastic cups.
Therefore, the concept of prebiotics, probiotics and synbiotics is “old news” to us, proud Vietnamese people with a long 4000-year period of heritage and culture. Finally, for your daily requirement of pre-, pro- and synbiotics, I would highly recommend a bowl of “cơm nguội, nước dưa chua với tôm kho”.