Probiotic yogurt as a Functional Food ARE PROBIOTICS IN YOGURT BENEFICIAL FOR HEALTH, REALLY?

STUDENTS:

- RAMOS QUINTO, NOELIA

- SOLORZANO HUARANGA, MARGOT

- VELASCO TORRES, HERNANA

- DONAYRE DÍAZ, AREF

- MALLQUI NIETO, LENHART

FIRST PART

PROBLEM:

ARE PROBIOTICS IN YOGHURT BENEFICIAL FOR HEALTH, REALLY?

VARIABLES:

- PROBIOTICS

- HEALTH

- YOGHURT

GENERAL OBJECTIVES:

- DISCLOSE THE ADVANTAGES AND DISADVANTAGES OF CONSUMPTION OF PROBIOTICS IN YOGHURT

SPECIFIC OBJECTIVES:

- DETERMINE THE BENEFITS OF CONSUMING PROBIOTICS IN YOGURT- DETERMINE THE NEGATIVE SIDE EFFECTS OF CONSUMPTION OF YOGHURT

PROBIOTICS AS PART OF A DIET

FRAMEWORK:

PROBIOTICS

Probiotics are described as “live microorganisms which, when administered in adequate amounts, confer a health benefit on the host.

Although there is a long history of health claims concerning living microorganisms in food, the term probiotic appeared only in the 1960s, and since then a number of definitions have appeared in the literature. The term probiotic, which comes from the Greek meaning “for life,” was originally used by Lilly and Stillwell in 1965 to describe substances secreted by one microorganism that stimulate the growth of another. It was later described by Parker in 1974 as “animal feed supplements that have a beneficial effect on the host animal by affecting its gut flora.” Fuller found this definition unsatisfactory as it did not exclude antibiotics, and redefined a probiotic as “a live microbial feed supplement that beneficially affects the host animal by improving its intestinal microbial balance.”Fuller’s definition was expanded to state that “a probiotic is a mono- or mixed culture of live microorganisms that, when applied to animal or man, affects the host beneficially by improving the properties of the indigenous microflora.”This definition stresses the importance of live microorganisms that occur in the mouth, gastrointestinal tract (GIT), upper respiratory or urogenital tracts and improve the health status of both man and animal.

In 1998, Guarner and Schaafsma introduced the concept of consuming adequate numbers of probiotics to reach target sites in the body, and described them as “living organisms that, upon ingestion in certain numbers, exert health effects beyond inherent general nutrition.

Then probiotics were defined as microbial cell preparations, or components of microbial cells, that have a beneficial effect on the health and well-being of the host. This definition emphasizes that probiotics can be either nonviable cells or parts of cells, because probiotics in these forms, as well as certain fermentation end-products and enzymes, have been shown to exert health benefits. Here, the importance is underlined of understanding the specific functions of probiotics in the host.

In 2001, a joint committee Food and Argriculture Organisation of the United Nations/World Health Organisation (FAO/WHO) expert consultation on health and nutritional properties of powder milk with live lactic acid bacteria redefined probiotics as “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host,” again highlighting the importance of viability. The group recognized that probiotics should be capable of exerting health benefits on the host through their activity in the human body. This definition is internationally recognized. Viability of probiotics in the final product is important, especially when it has been documented as one of the prerequisites for immune effects.

Recently, probiotics have been defined as “living microorganisms that resist gastric, bile, and pancreatic secretions; attach to epithelial cells; and colonize the human intestine.” The definition of probiotics has changed from the original one of being a live active culture beneficially affecting the host by improving its intestinal microbial balance, to the current concept based on the specific effects of clearly defined strains. This focuses attention on demonstrated clinical effects, which may be mediated either through probiotic effects on the intestinal immune system or through modulation of the gut microbiota at specific locations.

Probiotics are useful for:

1. Prevent and treat infectious diarrhea

2. Treatment of lactose intolerance

3. Improve the immune system

4. Prevent certain allergic manifestations

5. Reduce cholesterol levels

6. Prevent Colon Cancer

Probiotics or "friendly" bacteria are considered very safe as nutritional supplements. Probiotic bacteria, such as l. acidophilus, have been used successfully to treat dozens of common ailments with little risk of side effects, drug interactions, or other unwanted results. However, as all the nutritional supplements, there are some risks to taking large amounts of probiotics and supplements, which may not be suitable for all people.

The classification of probiotics can be compared to that of people. That is, genus corresponds to family name, species to given name, and strain to fingerprints.

The health benefits of probiotics are derived from specific bacterial strains that have demonstrated clinical efficacy; products may not be considered a probiotic unless they confer a proven health benefit.

Combining more than one probiotic strain in a single product does not necessarily enhance the benefits of each strain, and may in fact interfere with the activity already proven. Further studies are needed to determine the efficacy of combinations of strains.

The most used microorganisms like probiotics are showed in this table.

HEALTH BENEFITS OF FERMENTED MILK CONSUMPTION

Numerous reports and studies regarding the health benefits of yogurt and other fermented milk products have been published. Although the mechanisms behind such health claims are still being investigated, these benefits (on the immune or metabolic system) appear to be real. Many of the data collected thus far indicate that it is through the ingestion of the live LAB (Lactic Acid Bacteria) that these benefits are realized. The survival of bacteria administered in fermented milk products during passage through the human gut has been investigated intensely in recent years. Well-controlled, small-scale studies on diarrhea in both adults and infants have shown that probiotics are beneficial and that they survive in sufficient numbers to affect gut microbial metabolism. Probiotics are nonpathogenic microorganisms that, when ingested, exert a positive influence on the health or physiology of the host.

They can influence intestinal physiology either directly or indirectly through modulation of the endogenous ecosystem or immune system. Survival rates have been estimated at 20 to 40% for selected strains; the main obstacles to survival are gastric acidity and the action of bile salts. Although it is believed that the maximum probiotic effect can be achieved if the organisms adhere to intestinal mucosal cells, there is no evidence demonstrating that exogenously administered probiotics do adhere to the mucosal cells. Instead, they seem to pass into the feces without having adhered or multiplied. Thus, to obtain a continuous exogenous probiotic effect, the probiotic culture must be ingested daily. Certain exogenously administered substances enhance the action of both exogenous and endogenous probiotics. Human milk contains many substances that

stimulate the growth of bifidobacteria in vitro, especially in the small intestine of infants. However, it is unlikely that these substances function in the colon. Beneficial effects may thus accrue from exogenously administered probiotics, often administered with prebiotics (nondigestible food ingredients that benefit the host by selectively stimulating the growth or activity of one or a limited number of bacteria in the colon), or from endogenous bifidobacteria and lactobacilli, whose metabolic activity and growth may also be enhanced by the administration of prebiotics.

Studies that have shown a sufficient level of proof to enable probiotics to be used as treatments for gastrointestinal disturbances include:

1. Increase in tolerance of yogurt compared with milk in subjects with primary or secondary lactose maldigestion.

2. The use of Saccharomyces boulardii, Lactobacillus, and Enterococcus faecium to prevent or shorten the duration of antibiotic-associated diarrhea.

3. The use of S. boulardii to prevent further recurrence of Clostridium difficile- associated diarrhea

4. The use of fermented milk containing Lb. rhamnosus GG to shorten the duration of diarrhea in infants with rotavirus enteritis (and probably also in gastroenteritis of other causes)

Additional situations in which probiotics may be of value include mitigation of diarrhea of miscellaneous causes; prophylaxis of gastrointestinal infections, including traveler’s diarrhea; and immunomodulation. Trials in gastrointestinal diseases that involve the ecosystem, e.g., Helicobacter pylori infections, inflammatory bowel disease, and colon cancer are currently being performed. However, such treatments should be thoroughly studied and carefully given to patients, because there have been some case reports of the human infections caused by these probiotic bacteria. For example, Lb. lactis was reported to cause a liver abscess in a regularly yogurt-consuming patient whose colonic mucosa was damaged by an ingested bone. Lb. rhamnosus septicemia was reported in an immunocompromised patient treated with prolonged oral antibiotics for C. difficile diarrhea. The patient received a short course of live yogurt; nonetheless, the link between the yogurt consumed and the septicemia was not verified.

Interestingly, besides the gastrointestinal system, yogurt also enhances protective immunity against respiratory tract infections. For instance, yogurt supplementation with a balanced diet repletion in malnourished mice infected with Streptococcus pneumoniae improved many immunological parameters, and accelerated recovery from the infection compared to those mice repleted with a balanced diet alone. The authors suggested that three factors probably contribute to these effects. First, proteins in yogurt can be easily digested and absorbed because of the predigestion of protein during casein fermentation. Second, LAB can modulate common mucosal immune systems and, therefore, enhance mucosal immunity of the respiratory tract. Third, milk components produced during fermentation also exert immunostimulatory effects.

In a human study, Scientifics investigated the effects of a probiotic, fermented milk drink with Lb. GG, Bifidobacterium sp, Lb. acidophilus, and S. thermophilus on nasal colonization with pathogenic bacteria (Staphylococcus aureus, S. pneumoniae, and β-hemolytic streptococci). They demonstrated that daily consumption of probiotic yogurt for 3 weeks reduced nasal colonization with pathogenic bacteria, particularly Gram-positive bacteria, whereas volunteers who received

standard yogurt showed no difference in nasal colonization. Other examples of the influence of LAB on the respiratory system were shown in two different randomized, double-blind, placebo-controlled studies by Hatakka and de Vrese. The former group showed that there was a reduction in the number of children afflicted with respiratory tract infections in the group that received milk with Lb. GG, compared to those who drank milk without Lb. GG.

Michael De Vrese studied the effects of three LAB strains (Lb. gasseri, B. longum SP, and B. bifidum MF) on the common cold. They found that daily consumption of these LAB strains for 3 months reduced the severity and duration, but not incidence, of common cold episodes in 479 healthy adults. One of the most widely touted benefits of yogurt consumption is said to be the enhancement of the immune system. It has been proposed that LAB and fermented milk modulate certain parameters of both the nonspecific and specific immune responses. The link between these benefits and the immune system, however, has not been identified, and the mechanisms involved are still unknown.

Yoghurt and other fermented milks are foods that have achieved great popularity for various reasons , a greater awareness by consumers of the relationship between food and health , the importance of preventing disease, widespread search for a healthier old age and , of course, more scientific evidence of the effectiveness of these products .

SIDE EFFECTS

Digestive problems

Side effects of probiotics rarely occur, but the most common side effect is gastrointestinal upset. When large dose of probiotics is consumed, they adjust the balance of flora in the digestive tract or possibly gases resulting in abdominal discomfort. These side effects are usually temporary and ultimately benign. Generally, probiotics have the opposite effect: The probiotic supplements are useful in the treatment of gastrointestinal disorders such as bacterial retrovirus and irritable bowel syndrome. The process of biological adaptation, no probiotic supplements in itself is probably the cause of stomach problems.

Infection

It is theoretically possible that the live bacteria in probiotic supplements may colonize on the intestines, causing infection. Although no case reports of this complication occurs, it may be a risk to infants, the elderly and people with severely compromised immune systems. Treatment for this type of infection may require antibiotics. Because of this potential risk, people who are immune compromised should use caution when taking very large doses of probiotics. However, it should be noted that the risk of such side effects is minimal. Probiotics are normally consumed in foods and nutritional supplements for people of all ages and conditions, and has not been known that infection-related complications occurred.

Overstimulation

Overstimulation of the immune system is another complication that is theoretically possible, but has not been recorded so far. If the body is "wrong" with probiotics believing they are foreign invaders and infection can lead to a similar response to infection. This can cause a high white count, fever, fatigue and possibly even blood cells. Probiotics have not been well studied in people with autoimmune diseases. Although it may be beneficial for people with autoimmune disorders, people of this group may be at greater risk for this rare and unknown complication. Anyone with an autoimmune disorder or an extraordinarily aggressive immune system should use caution when taking large doses of probiotics.

Metabolic changes

Probiotics may slightly alter the function of the colon, resulting in unusual changes in metabolism. Some people may experience more frequent to take probiotics while others may experience a slowdown in bowel habits bowel movements. Metabolic changes can cause weight gain, weight loss or absorption problems. For most people using probiotics, adjustments in body metabolism will be positive and desired. However, if these changes are uncomfortable or injurious to health for the person taking probiotics, you should adjust your dose or stop taking the supplements.

Yoghurt

Yogurt is produced using active cultures of bacteria to ferment cream or milk. Yogurt that is produced in the United States is made with two specific live and active cultures of lactic acid bacteria (LAB)—Lactobacillus bulgaricus (Lb. bulgaricus) and Streptococcus thermophilus (S. thermophilus). These bacteria metabolize some of the milk sugar (lactose) in the milk into lactic acid. This action helps change the consistency of liquid milk into yogurt. The production of fermented milk, or yogurt, requires that the milk is first concentrated by the addition of dairy solids, evaporated, or membrane filtered. The mixture is then heated to destroy undesirable organisms, and cooled. Then, the starter cultures are added. Yogurt products may also have added ingredients such as sugar, sweeteners, fruits or vegetables, flavoring compounds, sodium chloride, coloring stabilizers, and preservatives. In the United States, Lb. bulgaricus and S. thermophilus are required by U.S.

The fermentation process involves the inoculation of pasteurized milk that has been enriched in milk protein with concentrated cultures of bacteria, which is then incubated at 40–44°C for 4–5 h. During fermentation, lactic acid is produced from lactose by the yogurt bacteria, the population of which increases 100- to 10,000-fold to a final concentration of approximately 109/mL. The reduction in pH, due to the production of lactic acid, causes a destabilization of the micellar casein at a pH of 5.1 to 5.2, with complete coagulation occurring around pH 4.6. At the desired final pH, the coagulated milk is cooled quickly to 4–10°C to slow down the fermentation process.

Fermentation of milk with LAB leads to specific organoleptic characteristics (taste, aroma) of the final product. The metabolism of LAB and the interactions between the selected strains are responsible for the production of lactic acid, the coagulation of milk proteins, and the production of various compounds. Variables such as temperature, pH, the presence of oxygen, and the composition of the milk further contribute to the particular features of a specific product.

Fermented milks exhibit a wide variety of textures ranging from liquid drinks such as kefir, koumiss, and acidophilus milk to semisolid or firm products including yogurt, filmjolk, villi, dahi, and leben.

Certain strains of S. thermophilus, Lb. bulgaricus, and other LAB, such as Lactococcus cremoris and some species of Leuconostoc, produce exocellular polysaccharides that modify the texture of a fermented milk product i.e., by increasing the viscosity or creating a “ropy” texture. Lactic acid is also responsible for the slightly tart taste of the fermented milk product, whereas the other characteristic flavors and aromas are additional results of LAB metabolism. For example, acetaldehyde provides the characteristic aroma of yogurt, whereas diacetyl, produced by Lc. Diacetylactis and Leuconostoc cremoris, impart a buttery taste to some fermented milks. Acetoin, acetone, lactones, and volatile acids are other important flavor components that may be present in certain fermented milks as by-products of bacterial metabolism.

There is a symbiotic relationship, also known as “protocooperation,” between S. thermophilus and Lb. bulgaricus, in which each species of bacteria stimulates the growth of the other. Lb. bulgaricus stimulates the growth of S. thermophilus by liberating amino acids and peptides from milk proteins; which enable S. thermophiles to grow faster in the early part of incubation. S. thermophilus in turn produces formic acid, which stimulates the growth of Lb. bulgaricus, resulting in a shortened fermentation time and a product with characteristics different than that of milk fermented with a single species.

SECOND PART

CHAPTER 1: PROBIOTICS

Probiotics

Probiotics are described as “live microorganisms which, when administered in adequate amounts, confer a health benefit on the host.

Generally probiotics are described as “live microorganisms which, when administered in adequate amounts, confer a health benefit on the host.” Examples of health benefits associated with the consumption of probiotics include a decrease in rotavirus shedding in infants, reductions in antibiotic-associated diarrhea, reduction in the incidence of childhood atopic eczema, and management of inflammatory bowel diseases such as Crohn’s disease. Foods containing probiotics, such as fermented milks, yogurts, and cheese, fall within the functional food category, which includes any fresh or processed food claimed to have health-promoting and/or disease-preventing properties beyond the basic nutritional function of supplying nutrients. The area of probiotics, prebiotics, and synbiotics represent the largest segment of the functional food market in Europe, Japan, and Australia.

Lactobacillus casei

In order to exert health benefits on the host, probiotics must be able to grow in the human intestine, and, therefore, should possess the capability to survive passage hrough the gastrointestinal tract (GIT), which involves exposure to hydrochloric acid in the stomach and bile in the small intestine. Lactobacillus and Bifidobacterium species are ideal probiotic candidates for incorporation into foods for human consumption. These microorganisms are known inhabitants of the gastrointestinal tract (GIT) and share a number of common traits such as acid and bile tolerance, the ability to adhere to intestinal cells, and GRAS status (generally regarded as safe).

A major challenge associated with the application of probiotic cultures in the development of functional foods is the retention of viability during processing. Given that probiotics are generally of intestinal origin, many such strains of bacteria are unsuitable for growth in dairy-based media, and are inactivated upon exposure to high temperatures, acid, or oxygen during dairy and food processing. The survival of bifidobacteria during processing can be particularly challenging, as these are strictly anaerobic microorganisms with complex nutritional requirements. Maintaining the viability (minimum numbers of probiotic cultures present in the final product recommended to be 10 colony forming units [CFU] per milliliter or even higher) and the activity of probiotic cultures in foods to the end of shelf life are two important criteria that must be fulfilled in order to provide efficacious probiotic food products.

Fermented dairy foods, including milk and yogurt, are among the most accepted food carriers for delivery of viable probiotic cultures to the human GIT. Because high levels of probiotics are recommended for efficacy of these products, preparation of bulk cultures is required. However, because probiotics are normally of intestinal origin, these cultures exhibit poor growth rates in synthetic and milk-based media. Spray drying and freeze drying are useful means of introducing the probiotic culture into these food systems. The use of such approaches in preparing cultures may impair viability and probiotic functionality due to the extent of cell injury that may occur during these processes upon exposure to extreme heating and drying, or freezing and drying.

Other approaches that have been used to improve the resistance of sensitive probiotic bacteria against adverse conditions during food processing, storage, and human ingestion include appropriate selection of acid-, bile-, and oxygen-resistant strains; stress adaptation; microencapsulation; incorporation of micronutrients and prebiotics; and genetic manipulation of probiotics, all of which will be discussed in the following sections.

Some of these bacteria are listed in the following table.

Classification

The classification of probiotics can be compared to that of people. That is, genus corresponds to family name, species to given name, and strain to fingerprints.

The health benefits of probiotics are derived from specific bacterial strains that have demonstrated clinical efficacy; products may not be considered a probiotic unless they confer a proven health benefit.

Combining more than one probiotic strain in a single product does not necessarily enhance the benefits of each strain, and may in fact interfere with the activity already proven. Further studies are needed to determine the efficacy of combinations of strains.

Probiotics are classed by group (e.g., lactic acid bacteria), genus (e.g., Bifidobacterium, Lactobacillus), species (e.g., casei, plantarum, bulgaricus, johnsonii) and strain (e.g., DN-173 010, DN-114 001, GG).

With many people having the same first or last name, identification can be difficult… but fingerprints are unique, allowing accurate identification of an individual.Probiotics work in much the same way: if we don’t know their strain, we can’t know which specific role they play in the body.

In order to better communicate with consumers, the names of certain strains have been modified by manufacturers. As an example, while the precise scientific name of the probiotic in DanActive yogourt isLactobacillus casei DN-114 001, what appears on the packaging is L. casei Defensis. This practice is common, with the intention being to help consumers understand the benefit or remember the probiotic more easily. That being said, a legitimate company will always specify the exact scientific name of the strain, and this is what consumers should be encouraged to look for.

Distinguishing between the different types of probiotics is important, since each strain plays a specific role. In fact, it is the strain that determines a probiotic’s role, and not just the genus.

The differences in properties between strains do not indicate with certainty that all their effects on the host would be different; however, this possibility must be considered, at least until proved otherwise. It is not impossible that the presence of a well identified active substance in a probiotic may be shown to be sufficient to permit a reliable prediction that an effect will be obtained. However, this is unlikely in the near future and will require solid verification. It is therefore generally accepted that the effects of one strain cannot be extrapolated to another. In other words, clinical studies on the strain itself are required before any claim can be made.

Producers can use this characteristic to protect the specificities of their products. Advertising or claims referring to similar strains must not be used in scientific or promotional dossiers or brochures, neither in their evaluations.

The most used microorganisms like probiotics are showed in this table.

Improvements for survival of probiotic

Heat from pelleting and long storage of products may render the non-viability of the product. For improving the survival of probiotic cultures following practices has been applied

1. - Encapsulation:

Encapsulation has proven very successful in improving the survival of probiotics in FF. Although encapsulation in alginate gels protects cells during freezing, heating, and storage in acid foods, there are few commercial products on the market based on this technology. Producers of probiotics have preferred the spraycoating technology to market their products. Spray-coating is carried out by vaporizing a protective compound on the surface of a probiotic-containing dried particle. The spray-coated products are very effective in enhancing survival of the cells in the gastrointestinal (GI) tract, ideally releasing the biomass at a predetermined site. There is increasing evidence that coating also helps probiotic bacteria to better survive heat processes as well as storage at room temperature.

2. - Prebiotics:

Prebiotics are non-digestible food ingredients that stimulate the growth and/or activity of bacteria in the digestive system in ways claimed to be beneficial to health. They were first identified and named by Marcel Roberfroid in 1995.

A prebiotic effect occurs when there is an increase in the activity of healthy bacteria in the human intestine. The prebiotics stimulate the growth of healthy such as bifidobacteria and lactobacilli in the gut and increase resistance to invading pathogens. This effect is induced by consuming functional foods that contain prebiotics. These foods induce metabolic activity, leading

to health improvements. Healthy bacteria in the intestine can combat unwanted bacteria, providing a number of health benefits.

Prebiotics are non-digestible but fermentable oligosaccharides that are specifically designed to change the composition and activity of the intestinal microbiota or microflora with prospect to promote the health of the host.

Synbiotics: A synbiotics is a combination of one or more probiotics and prebiotics.

Desirable probiotics characteristics

Microbes from many different genera are being used as probiotics, including Lactobacillus, Bifidobacterium, Propionibacterium, Bacillus, Escherichia, Enterococcus, and Saccharomyces. Lactobacilli are the most commonly used probiotics in food, whereas bifidobacteria are used less, as they are sensitive to oxygen and have more strict growth requirements, making them technologically more unsuitable for use. With the exception of propionibacteria and enterococci, the other species mentioned are not usually used in fermented food products, but as probiotics in dietary supplements or in capsules, powders, etc. Ideally, a microorganism should meet a number of predefined criteria in order to be considered as probiotic.

The microbes administered should be safe, have GRAS status (Generally Recognized As Safe), and also have a long history of safe use in foods. All probiotic strains should have nonpathogenic properties, and ideally should exhibit tolerance to antimicrobial substances, but should not be able to transmit such resistance to other bacteria.

Adherent probiotic strains are desirable because they have a greater chance of becoming established in the GIT, thus enhancing their probiotic effect. Adhesion to the intestinal mucosa is considered important for immune modulation (the intestine being the largest immune organ of the body), and for pathogen exclusion by stimulating their removal from the infected intestinal tract. Two human Lactobacillus strains were examined for adherence properties in a study by Fernandez, Boris, and Barbes. Both strains adhered to Caco-2 cells, through glycoproteins in Lactobacillus gasseri, and through carbohydrates in Lb. acidophilus, and both strains were able to inhibit certain enteropathogens, including Salmonella, Listeria, and Campylobacter without disturbing the normal microbiota. They also found in this study that the Lb. gasseri that strongly

attached to the intestinal Caco-2 cells inhibited the attachment of Escherichia coli 0111 under the condition of exclusion. Ability to survive passage through the GIT is a requirement in order to confer health benefits to the host. Acid tolerance, tolerance to human gastric juice, and bile tolerance should all be established by using in vitro methods.

Probiotic microorganisms should also be technologically suitable for incorporation into food products, such that they retain both viability and efficacy in that food product (to a commercial scale) prior to and following consumption. Probiotics should be capable of surviving industrial applications (e.g., common dairy processing methods using pharmaceutical manufacturing protocols), of thriving in the product to the end of shelf life, and of having an acceptable taste throughout the storage time. Above all, probiotic food products must demonstrate efficacy in controlled and validated clinical trials to prove that the probiotic characteristics were not altered or lost during manufacturing.

CONCLUSIONS

Probiotic research has expanded rapidly over the past few years. One of the many reasons for this is the heightened awareness of their clinically proven health-promoting effects in humans, and hence the growing interest in the incorporation of probiotic microorganisms into food products.

The mechanisms by which functional microbes and ingredients affect human gut health are still largely unknown. The knowledge acquired by genomics on the genetics and physiology of a probiotic strain can be used for strain improvement.

The great challenge of growing probiotic cultures at a manufacturing plant can only be tackled by using a holistic approach and having qualified personnel and sophisticated quality control laboratories.

Many species in such fermented foods have the potential to be probiotic, health attributes can only be expected if strains having documented clinical effects are used.

A higher number of strains is not proof of greater efficacy.

The effect of one strain cannot be extrapolated to another.

Some strains are not recommended for human use. Species from bacterial genera like Bacillus cereus and Enterococcus have also been used as probiotics, but because these species contain strains known to be pathogenic (this is particularly true of Enterococcus), there are concerns for their safe use. The onus must be on producers to prove that their strains are not pathogenic.

RECOMMENDATION

Foods or supplements containing probiotics would list the following information on their labels:

Description of genus, species and strain.

The minimum viable numbers of each probiotic strain at the end of the product’s shelf life.

A suggested serving size, which must deliver an effective dose of probiotics relative to the health claim.

The health claim.

Proper storage conditions.

BIBLIOGRAPHY

EDWARD R. FARNWORTH, “Handbook of Fermented Functional Food”. Second Edition. Ed. CRC Press, 2008. Pages 1 – 25, 129 – 165, 513 – 537.

CLYDESDALE, F., “Functional foods: opportunities and challenges”, Full report at: www.ift.org, IFT Expert Reports, 2005. Pages 58 – 35.