Probiotics—Good Bacteria Meet Functional Foods

Europeans and Asians, in particular, have long known about the health benefits of pre- and probiotics. Now, manufacturers are eyeing the fertile North American market for product penetration. Gregor Reid, PhD, tells how science is the backbone of this growth sector.

The famous words of New York Tribune editor Horace Greeley, "Go West, young man," are most appropriate for today's manufacturers of probiotics. After many years of popularity in eastern Europe and Japan, makers of probiotic drinks, in just six years, have created a $350 million market in western Europe.

North Americans are just now learning about the probiotic approach to intestinal health, and manufacturers and distributors are scoping out the world's great marketplace: the North American free-trade zone.

The basic notion behind probiotics is pretty straightforward: restore the depleted ecology of the intestine with new, healthful bacteria. More than 100 years after Elie Metchnikoff, as director of the Pasteur Institute, identified the benefits of Lactobacillus bacteria, the concept has been expanded to define health benefits far beyond the gut.

Indeed, the Food and Agriculture Organisation of the United Nations (FAO) and the World Health Organisation (WHO), following a request from member nations, prepared a report and a set of guidelines for use of probiotics in the new millennium.1,2 They now define probiotics as "live microorganisms which, when administered in adequate amounts, confer a health benefit on the host." Several aspects of this definition are critical to future growth of the field.

Defining The Field
First, with respect to product contents, it is critical that probiotics be living at the time of use, and the viable colony-forming unit count must be at the level proven to confer a health benefit in humans or animals. No longer is it sufficient to state a viable count at the time of manufacture. The consumer needs to know the count at time of use. Consumers have no way of knowing how a product is handled prior to its purchase or how many organisms are alive when they use it.

In a yoghurt format, likely 107,8 probiotic organisms (added after the yoghurt is made) could be delivered per dose, although in capsule or other freeze-dried format more than 109 can be delivered per dose. Few dosage studies have been undertaken, but one showed that a physiological effect on the vaginal flora following oral intake required at least 108 live Lactobacillus rhamnosus GR-1 and L. fermentum RC-14 per daily dose.3 In terms of gut health, at least 109 of L. rhamnosus GG or L. reuteri (apparently strain SD 2112) appear to be required to reduce the duration of rotaviral diarrhoea in children, yet even at this dose the effect against bacterial gastroenteritis is questionable.4,5

Probiotics have long been promoted as improving the host intestinal microbial balance, thereby leading to improved general health. However, no study has actually tested this theory, and indeed, general health is difficult to measure. Companies such as Yakult, whose probiotic beverage product reaches 24 million people per day, would be well placed to undertake a large study to determine benefits of their product in healthy people vs. nonusers of probiotics.

For this reason, in part, current conceptions of probiotic benefits must be based on target- and site-specific effects of clearly defined strains. Although this may be due to differences in adhesion and immunological effects,6 no clinical studies have proven the precise mode of action. Nevertheless, just as E. coli 0157: H7 causes gastroenteritis and not urinary tract infection, and type 1 and P fimbriated E. coli cause the latter and not the former, so too Lactobacilli strains differ in the effects on the gut and urogenital tract even when they belong to the same species.7,8,9

The FAO/WHO Expert Consultation lists benefits that had substantial support from peer-reviewed publication of human studies.1 Essentially, these are to prevent and reduce the duration of diarrhoea, prevent onset of atopic dermatitis, and prevent urogenital infections. Promising data exist on suppressing Helicobacter pylori stomach infections, reducing the risk of certain cancers, modulating mucosal immunity, and lowering serum cholesterol and oxaluria. Remediation of irritable bowel syndrome and inflammatory bowel disease is possible, but it is too early to define the probiotic organisms that can be effective. Studies currently under way might achieve this. In all likelihood, this will require a multispecies probiotic approach. In that case, the formulation must be reproducible, with the role of each constituent known and documented.

The host microflora is often badly disrupted when patients are seriously ill or hospitalised. In a series of studies, an L. plantarum 299 strain was shown to minimise surgical complications. Researchers in a double-blind, placebo-controlled study of 45 London patients with severe acute pancreatitis found significantly reduced pancreatic sepsis as well as reduced number of surgical interventions after supplementing with L. plantarum 299.10 Similarly, a prospective, randomised, placebo-controlled study of 95 patients in Germany found L. plantarum 299 reduced bacterial translocation and minimised the incidence of infections after liver transplantation, leading researchers to speculate that supplementation should begin while patients are on the waiting list for transplantation.11 A small group of German surgery patients experienced reduced post-surgical infections upon taking an enteral solution containing oat fibre and either live or heat-killed L. plantarum 299. The only difference between the two probiotics groups was the live group received antibiotics for a significantly shorter time.12 Given the enormous morbidity, mortality and economic impact associated with hospitalisation and certain surgical procedures, probiotic use could become a vital component of patient management in the future.

Of critical importance, the microorganisms claimed as probiotics must be defined using standard molecular techniques. Many producers will need specialised labs to do this work, but can then properly name the organisms on product labels. For example, some products claim to contain L. sporogenes, when this organism does not even exist and lactobacilli do not form spores.13 Another known example is that L. acidophilus strains may actually be L. crispatus, L. gasseri, L. johnsonii, L. gallinarum or L. amylovorus because subtle differences have been found in their DNA homology.14 Indeed, L. helveticus, L. iners and L. amylolyticus are all phenotypically highly similar to the seven strains in the L. acidophilus group.15

The organisms must then be given a designated number or identity, such as L. rhamnosus GG. No two organisms are identical, and companies that make loose claims based on some generic link to L. acidophilus or historical studies performed on other organisms such as L. rhamnosus GG are only confusing consumers and health professionals. If a company has a promising strain of L. rhamnosus, it has to prove that it has similar properties to those published for LGG, especially if claims are being made based on areas where LGG has shown great promise, such as diarrhoea prevention and treatment as stated above, and down-regulation of the milk-induced inflammatory response in milk-hypersensitive subjects.16

Encapsulation and preservation techniques will soon make products capable of being directed to specific sites in the body.
This then enables the consumer or caregiver to read peer-reviewed publications on these organisms and verify that its present product formulation offers specific health benefits for a defined user group. This helps nullify the unethical practice of some companies, which state on their Web sites that their probiotics cure or treat a range of diseases from cancers to osteoporosis, candidiasis, and/or bowel and skin ailments, without any published evidence. 17This misinforms consumers and denigrates the field.

Upon reading these comments, representatives of smaller companies may feel the anxiety of not having the funds necessary to conduct extensive clinical trials, but how can any company ethically sell an untested product? Human (or livestock, if that is the target population) trials need not be extensive, but they must be more than testimonials that do not take into account the potential placebo effects. The FAO/WHO Guidelines provide an outline of what will be required.2

The greatest potential for market growth of probiotics, estimated to be a staggering $120 million per month,18 will be achieved through broader buy-in from physicians, pharmacists and other professional health caregivers. This can happen only through valid scientific and clinical verification. In an era when well-educated consumers, especially baby boomer women, are learning about health through the Internet, probiotic producers must not underestimate the potential for market demand and the need for solid scientific reckoning of their product.

Technological Advances
Exposure to oxygen, light, temperature changes and humidity, as well as stomach acidity, can easily degrade and destroy probiotic microorganisms. The biggest challenge is delivering the promised number of cells to the intestine. A number of innovations address this issue.

  • Shelf Stability essentially means that dried organisms must be blocked from exposure to water molecules and extreme heat. Microencapsulation techniques, for example the technique used by Montreal's Institut Rosell-Lallemand, provide a means to isolate clumps of bacteria, thereby providing greater protection from extreme conditions. Preparing bacteria is a critical process and producers should use good manufacturing practices (GMP) and Food and Drug Administration (FDA)-approved plants and minimise the drop-off in viability after drying bacteria.
  • Coating Techniques make it possible to protect the organisms by binding the sugars (for example, Chr. Hansen's technology) that do not allow hydration until the probiotics reach the alkaline pH of the colon. Enteric coating of capsules can protect products against stomach acidity and bile salts, or be designed to take advantage of acidity so that the product dissolves in acid,19 a technique that might be useful for treating H. pylori infections in the stomach.

    It is important to note that room temperature in northern Sweden in February is not the same as in Italy in July. Thus, manufacturers should consider climactic variations across regions when establishing a product's shelf life. Tests for bacterial survival, while useful in accelerated lab tests that reach 40°C (104°F) or higher, are best determined following one to two years in use.

  • Encapsulation And Preservation Techniques, such as those being developed by Canacure in Montreal and Universal Preservation Technologies Inc in California, will soon make products capable of being directed to specific sites in the body. This should make it possible to preserve and protect microorganisms for specific treatment of diseases such as H. pylori infections in the stomach, and for targeting inflammatory bowel disorders, pouchitis, vaginitis and throat infections. It should be noted that calcium alginate, used for microencapsulation in conjunction with Hi-Maize starch as a prebiotic, and glycerol, used as a cryo-protectant, can improve survival of bacteria in the capsule, yet have no effect on survival in acid or bile.20 This illustrates the complexity of these processes and the need to authenticate each outcome.

    It is noteworthy to mention that benefits from these stabilisation techniques remain to be clinically demonstrated.

    Foods You Can Use
    For reasons ranging from obesity epidemics to escalating health care budgets, from pharmaceutical side effects to antibiotic overuse in both humans and livestock, the opportunities for probiotics have never been greater. Probiotics and functional foods have the potential within 20 years to significantly influence the health of humanity.

    Amongst the new generation of products are those designed for the lunch-pack market, many of which are packaged with children in mind. Combine a milk-based probiotic drink like Yakult or Actimel (due for a North American launch within two years), probiotic cheeses such as the ones being developed at TEAGASC in Ireland21 or Bio-Cheese in Australia using L. rhamnosus HN001; almonds, organic fruits, and slices of free-range, drug-free chicken on sugar-free, multi-grain flax bread, and you have the seeds of a healthy lunch.

    As Stig Bengmark, MD, a surgeon and developer of Probi's L. plantarum 299V, rightly noted, Palaeolithic humans ate significantly less salt, sugar and fat than we do, and they consumed far more beneficial bacteria.22 As a society, we have paid little attention nutritionally to this latter ingredient, and it would behoove the food and pharmaceutical industries to catch the trend early on.

    We have more bacterial cells in our body than human cells, yet we do not purposely nurture these microbes. On the contrary, we use so many antiseptics, preservatives, pesticides, herbicides, antibiotics and disinfectants that only the drug-resistant pathogens tend to thrive. It is no wonder that there are so many cases of post-antibiotic yeast infections and Clostridium difficile gastroenteritis.

    Opportunities And Threats
    The FAO/WHO and subsequent Codex initiatives should finally bring a semblance of standardisation and quality to the probiotic field. Likewise, scientific advances will produce new products, while consumer education and demands will support expansive business opportunities. The greater challenge is in determining when probiotics should be taken.

    Clearly, one key stage for establishing the commensal microflora is at birth and the subsequent first months of life when the immune system is developing. Manipulating the intestinal microflora of the infant may have long-term benefits if the flora of the adult is determined by events in this critical period of gut colonisation, particularly the days after birth and during weaning when flora composition diversifies.23

    In addition to the ethical issues of purposely colonising every baby at birth, many practical problems arise. Which flora is appropriate for which person? What roles do genetics and receptor-site availability play? If the body is designed to select certain strains, as appears to be the case in the oral cavity, then it may be impossible to significantly modify the gut flora, even following select probiotic use at birth. It would be useful to have additional studies that show how probiotics at birth can, for instance, prevent atopic dermatitis.24

    It may be 20 years or more before we have the capability of designing an ideal method of optimising health from birth. For this reason, we need to forge ahead with research into this field. In premature, low-birth-weight babies, the development of necrotising enterocolitis is so devastating that we should reassess our clinical practices. Studies have shown the incidence can be cut in half when physicians administer the species L. acidophilus and Bifidobacterium infantis.25

    A second challenge will be at the regulatory level. The US Food and Drug Administration, for example, does not know how best to handle probiotics and has developed a bureaucratic system fearful of errors rather than one that is open to new concepts. If probiotics are not foods and not drugs, what are they? If probiotic foods have been shown to have functional health benefits, why can't medical disease-based claims be made without drug designation and 10 years of research and development? Perhaps DSHEA needs to be amended to address this shortcoming.

    In the past five years, there have been more than 800 peer-reviewed articles on probiotics, in contrast to 85 papers the previous 25 years. Scientific excellence, quality manufacturing, honest marketing, vision and flexibility in funding and regulatory agencies, and progressive consumer education will ensure that pre-and probiotics flourish and find their appropriate place in health restoration and maintenance.

    Gregor Reid, PhD, MBA, is director of the Canadian Research and Development Centre for Probiotics at Lawson Health Research Institute and professor at the University of Western Ontario, London, Canada. He is the inventor of several pending and issued patents describing the use of probiotics, and is a principal in Urex Biotech Inc, a Canadian probiotics and functional foods company. [email protected]


    1. FAO/WHO. Evaluation of health and nutritional properties of powder milk and live lactic acid bacteria. Food and Agriculture Organization of the United Nations and World Health Organization Expert Consultation Report, 2001.

    2. FAO/WHO. Guidelines for the evaluation of probiotics in food. Food and Agriculture Organization of the United Nations and World Health Organization Working Group Report, 2002.

    3. Reid G, et al. Probiotic Lactobacillus dose required to restore and maintain a normal vaginal flora. FEMS Immunol. Med. Microbiol 2001;32:37-41.

    4. Shornikova AV, et al. A trial in the Karelian Republic of oral rehydration and Lactobacillus GG for treatment of acute diarrhoea. Acta Paediatr 1997;86(5):460-5.

    5. Shornikova AV, et al. Lactobacillus reuteri as a therapeutic agent in acute diarrhea in young children. J Pediatr Gastroenterol Nutr 1997;24(4):399-404.

    6. Isolauri E, et al. Role of probiotics in food hypersensitivity. Curr Opin Allergy Clin Immunol 2002 Jun;2(3):263-71.

    7. Reid G, Bruce AW. Selection of Lactobacillus strains for urogenital probiotic applications. J Infect Dis 2001;183(Suppl 1):S77-80.

    8. Cadieux P, et al. Lactobacillus strains and vaginal ecology. JAMA 2002;287:1940-1.

    9. Reid G, et al. Ability of Lactobacillus GR-1 and RC-14 to stimulate host defences and reduce gut translocation and infectivity of Salmonella typhimurium. Nutraceut Food 2002;7:168-73.

    10. Olah A, et al. Randomized clinical trial of specific Lactobacillus and fibre supplement to early enteral nutrition in patients with acute pancreatitis. Br J Surg 2002 Sep;89(9):1103-7.

    11. Rayes N, et al. Early enteral supply of Lactobacillus and fiber versus selective bowel decontamination: a controlled trial in liver transplant recipients. Transplantation 2002 Jul 15;74(1):123-7.

    12. Rayes N, et al. Early enteral supply of fiber and lactobacilli versus conventional nutrition: a controlled trial in patients with major abdominal surgery. Nutrition 2002 Jul-Aug;18(7-8):609-15.

    13. Sanders ME, et al. "Lactobacillus sporogenes" is not a lactobacillus probiotic. ASM News 2001;67:385-6.

    14. Holzapfel WH, et al. Taxonomy and important features of probiotic microorganisms in food and nutrition. Am J Clin Nutr 2001 Feb;73(2 Suppl):365S-373S.

    15. Gancheva A, et al. A polyphasic approach towards the identification of strains belonging to Lactobacillus acidophilus and related species. Syst Appl Microbiol 1999 Dec;22(4):573-85.

    16. Pelto L. Probiotic bacteria down-regulate the milk-induced inflammatory response in milk-hypersensitive subjects but have an immunostimulatory effect on healthy subjects. Clin Exp Allergy 1998:28;1474-9.

    17. Reid G, et al. Urogenital lactobacilli probiotics, reliability and regulatory issues. J Dairy Sci 2001;84(E Suppl):E164-9.

    18. Nutrition Business Journal, Nov. 2001.

    19. Leopold CS, Eikeler D. Basic coating polymers for the colon-specific drug delivery in inflammatory bowel disease. Drug Dev Ind Pharm 2000 Dec;26(12):1239-46.

    20. Sultana K, et al. Encapsulation of probiotic bacteria with alginate-starch and evaluation of survival in simulated gastrointestinal conditions and in yoghurt. Int J Food Microbiol 2000 Dec 5;62(1-2):47-55.

    21. Gardiner G, et al. Evaluation of cheddar cheese as a food carrier for delivery of a probiotic strain to the gastrointestinal tract. J Dairy Sci 1999 Jul;82(7):1379-87.

    22. Bengmark S. Use of prebiotics, probiotics and synbiotics in clinical immunonutrition. Proceedings, International Symposium on Food, Nutrition and Health for the 21st Century, Korea, 2002 Dec 7-8;187-213.

    23. Martin F, et al. Investigation of bacterial colonisation of the colon in breast fed infants using novel techniques. Proc Nutr Soc 2000;59:62A.

    24. Kalliomaki M, et al. Probiotics in primary prevention of atopic disease: a randomized, placebo-controlled trial. Lancet 2001 Apr 7;357(9262):1076-9.

    25. Hoyos AB. Reduced incidence of necrotizing enterocolitis associated with enteral administration of Lactobacillus acidophilus and Bifidobacterium infantis to neonates in an intensive care unit. Int J Infect Dis 1999;3:197-202.

    ISAPP Is Formed

    In May, the International Scientific Association for Probiotics and Prebiotics (ISAPP) was officially launched with a scientific meeting in London, Ontario, Canada. Sixty-five of the world's best-known scientists in this field participated. The following are some details on the new organisation:

  • A board of directors is chaired by Mary Ellen Sanders, PhD. There is an advisory council, but no official membership or lobbyists. The organisational mandate is to foster and disseminate functional research findings on probiotics and prebiotics in humans and animals. ISAPP plans to hold an annual symposium.

  • ISAPP plans to publish information targeted at the scientific and clinical communities, as well as related industries. The first article from ISAPP has been published in American Society for Microbiology News 2002 August.

  • See the ISAPP Web site under construction at or other links through:

  • Prebiotic Plethora Colonises The Field

    The current generation of prebiotic oligosaccharides extracted from plants or synthesised from sucrose or lactose by enzymatic methods can also provide health benefits through foods. Prebiotics were originally defined as "microbial food supplements that benefit the host by improving its intestinal microbial balance,"1 but this may soon be revised with qualifiers such as 'butyrogenic prebiotic,' 'bifidogenic prebiotic,' 'anticancer prebiotic' or 'immunomodulating prebiotic.' The concept is that bifidobacteria and lactobacilli utilise the sugars for metabolism, whereas pathogenic organisms and the host do not. However, this is a bit simplistic and much remains to be done to fully understand the role that prebiotics have in human and animal health, the dosage required and the specific benefits accrued. In particular, if the alteration in the gut increases the growth of one strain of bifidobacteria and decreases that of another strain, as one unpublished study appears to show (Burton, J personal communication), then it will be critical to make sure that the most beneficial organisms within the species are enhanced.

    Already, fructo-oligosaccharides, galacto-oligosaccharides and lactulose are recognised for their bifidogenic effects in laboratory, animal and human trials.2 In Japan, a much broader list of prebiotics exists, including soyoligosaccharides, xylo-oligosaccharides, isomalto-oligosaccharides, gentio-oligosaccharides, lactosucrose and gluco-oligosaccharides. Resistant starches and some sugar alcohols also have been touted as prebiotics, while new prebiotics with multiple functionality are under development.

    Advances will come from carbohydrate chemistry, microbial physiology and biochemical engineering, as well as through a better understanding of how specific strains within the intestine react to prebiotics and how this affects short- and long-term health. The extent to which ingestion of a specific amount of a prebiotic, such as inulin, translates into a specific health benefit should be the subject of future clinical trials.


    1. Gibson GR, Roberfroid MB. Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics. J Nutr 1995 Jun;125(6):1401-12.

    2. Gibson GR, et al. Prebiotics: New developments in functional foods. Chandos Publishing Limited, Oxford; 2000.

    Intellectual Property: New Avenues In Probiotics

    Scientific research demonstrating the clinical efficacy of probiotics has spawned further research into the development of new technologies and applications. Along with this, strict government regulations and copious patent filings have emerged.

    In Canada, the new Natural Health Products Directorate (NHPD) specifically targets probiotics as one of eight main categories. Among the demands by the NHPD is the need for GMP site licensing. Scandinavian countries have enforced new Novel Foods regulations that include probiotic-containing foods.

    In the EU, plans for new regulations have commenced with a large scientific investigation called ProEUHealth. This multimillion-dollar and multisite project will examine not only clinical efficacy but also commercial strain identification and safety. ( Presumably, any bacteria not part of these studies may find itself on an excluded list when the new EU regulations are approved. These international regulations may make exporting US products difficult. This would be unfortunate because the North Americans appear to be leading this renewed interest in probiotics through improved scientific documentation of efficacy and development of new technologies that ensure that high numbers of viable bacteria reach their intended target.

    Technologies such as STAR, an enteric-coating system, are designed to allow the probiotic capsules to bypass stomach acid. Microencapsulation systems (W0 01/68808) allow probiotics to withstand food processing so they can be used in yoghurts, chocolates, drink powders and extruded foods. Patent application US20020119237 employs vegetable oil, fish oil and antioxidants such as tocopherol to protect probiotics from the harsh environment of the food processing facility or bubbling acid of the stomach.

    With the advent of new technologies to assure high viability, an exponential number of application patents have been submitted. Leading this probiotics patents race is Nestlé & Nestec, which has been patenting everything from applications in frozen desserts (US6399124), in dehydrated foods (US6200609) and in cereals (US5968569) to probiotics for stimulating the skin's immune system (AU2058702).

    More novel patent applications have been filed by Pierre Fabre, which combines probiotics with soy isoflavones to treat menopause (US2002114786), and by Ellen R. Bolte, who claims probiotics have a positive impact in autistic patients (US2002013270).

    Of greater note is a recent international patent filed (WO 02/070670) by Probionics Corp in Korea describing a new strain of Lactobacillus reuteri (Probio-16) with claimed antirotavirus and anti-diarrhoeal activity. This composition patent, if issued, offers the greatest degree of competitive insulation, surpassing method-of-use patents.

    Under intense pressure to succeed, probiotics manufacturers are now at a critical developmental period. If all goes well, probiotics could gain universal acceptance and consumers may one day read product labels with specified recommended daily intakes. However, if probiotics do not meet the new consumer demands and government-imposed regulations, they may return to relative obscurity amongst the background of thousands of other promising alternative therapy products.

    —Thomas Tompkins, PhD
    Director of Research
    Institut Rosell-Lallemand

    Marketing Applications: Seed, Feed And Weed

    From the marketer's or product developer's point of view, three separate categories should to be kept under surveillance: new organisms (pay attention to genus, species and strain—seed), new prebiotics (food for organisms—feed) and any additive or synergistic components that may remove or retard pathogenic organisms—weed. It is possible to use materials and ingredients from these three groups individually, or combine any or all of the three, to deliver a positive consumer experience product.

    Several macrotrends apply to this equation. First is the necesssity of brand-specific research. Second is the consideration of consumer taste and convenience. Third is cost to the consumer. Fourth is the state of intellectual property . How do these apply?

    Dating back to the early 1990s, at least one company has had this concept firmly in mind. Metagenics, based in San Clemente, California, has filed several patents in the area of combinations of seed, feed and weed.

    An important issue to consider is whether effective combination volumes will be too expensive for the consumer to purchase. Emerging prebiotic ingredients that are both low in cost and have been demonstrated to be effective in feeding probiotic organisms may be a more cost-effective, as well as efficient, method.

    Another consideration is how the consumer will ingest these products and how much of the probiotics are needed. Beverage-based products have flourished around the globe, and it is easy to predict that the early brand successes in regions lacking these products will soon bloom as beverages (pun intended). If so, taste will play its usual mammoth role in consumer adoption and consumption.

    Lastly, all of these components must be carefully directed and combined with an evidence package (science +) that's tied uniquely to the brand and is easy for a consumer to understand and relate to. It also must be laser-targeted to the individual consumers that already understand the basic principles and concepts of seed, feed and weed. Large brands in the US, such as Nestle's LC-1 and ConAgra's LGG, have failed or remain stagnant in some part due to these issues.

    Probiotics may be our best defense against a world under threat from viruses, prions and who knows what else. These pro-bugs hold great promise in their ability to be applied to foods, supplements and even personal care products.

    —Tim Avila

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