Gut Health, Good Health
by Jenifer Hunt

Humans are host to billions of diverse species of microorganisms that inhabit the skin, gastrointestinal (GI) tract, urogenital tract and mouth, conveying either a beneficial, neutral or negative effect on health. Beneficial bacteria, termed “probiotics” from the Greek expression “for life,” act in a number of ways to improve digestive health and promote general physical well-being. Optimal health requires a balance of beneficial bacteria over their pathogenic counterparts, which are a known cause of disease, affecting not only the bowel, but many health functions. Probiotics are live microorganisms that benefit the host by improving the body’s microflora, and are naturally found in yogurt, buttermilk, kefir, tempeh, miso, kimchi, sauerkraut, and other cultured and fermented foods.

Unlike disease-promoting “germs,” probiotics actively protect against the spread of, and increase resistance to, pathogenic bacteria and yeasts. By positively influencing intestinal microflora, probiotics have been found to reduce risk for many gastrointestinal diseases and disorders including lactose intolerance, diarrhea and symptoms associated with irritable bowel syndrome (IBS); may help lower blood pressure and blood cholesterol levels; and appear to boost immune function by decreasing infection and allergenic reactions caused by pathogens and antigens that permeate the intestinal lining. Probiotics have also been found to increase absorption of certain nutrients including calcium, copper, iron and magnesium, and help digest food components not properly broken down in the small intestine, such as lactose.

Healthy intestinal microflora should consist of a majority of lactobacilli and bifidobacteria. Supplementation with the probiotic strain L. acidophilus balances microflora, thereby producing lactic acid, acetic acid, hydrogen peroxide, enzymes and B vitamins as metabolic by-products. This lowers intestinal pH levels, creating a less desirable climate for pathogenic bacteria.

The probiotic Bifidobacterium bifidum is the predominant organism in the intestinal microflora and creates a healthy environment for the body to manufacture B complex vitamins and vitamin K. Use of antibiotics destroys probiotics along with the intended harmful bacteria and upsets the body’s microflora. This can result in the production of high levels of ammonia which can irritate intestinal membranes and lead to digestive upset. Because B. bifidum and other probiotics assist in digestion, decreased populations may lead to digestive disorders, which can cause excessive production of histamine, a trigger of allergic symptoms.1 Because B. bifidum also destroys pathogenic yeasts, vaginal yeast infections respond favorably to local application. Children and adults with liver disorders can receive a great benefit from B. bifidum supplementation, as improved digestion reduces strain on the liver, thereby making it particularly useful in the treatment of hepatitis and cirrhosis.2

Like probiotics, prebiotics such as inulin, arabinogalactan, lactulose and oligofructose deliver important health benefits by positively affecting intestinal health. Prebiotics are often referred to as a companion nutrient to probiotics because they directly affect bacteria proliferation by acting as a food source. Prebiotics also confer specific beneficial physiological effects, including producing nutritious short-chain fatty acids (SCFA).3 The criteria used to classify a food component as a prebiotic are resistance to digestion, hydrolysis and fermentation by colonic microflora, and selective stimulation of growth of one or a limited number of bacteria.4

To promote health, prebiotics must be worked upon by probiotic bacteria strains with clearly identified, health promoting properties, such as lactobacilli and bidifobacteria strains, and not pathogenic bacteria strains.5 The beneficial effects of inulin-type fructans, including native inulin, oligofructose and fructooligosaccharides (FOS), are backed by strong scientific research, and are considered prototypes of prebiotics. Inulin-type fructans are popular ingredients in manufactured prebiotics foods, and are found in many natural food sources including wheat, onion, banana, garlic, leeks and chicory. “Inulin is a very versatile ingredient with many health-promoting benefits,” said Pam Stauffer, marketing programs manager at Cargill. Because the health benefits of both probiotics and prebiotics extend beyond simply supplying the body with nutrients and deliver “functional” physiologic benefits, foods containing these substances are often considered “functional foods.”

Eli Metchnikoff, a Nobel prize-winning Russian physiologist and director of the Pasteur Institute, proposed nearly a century ago in his work The Prolongation of Life that Bulgarian peasants owed their long, healthy lives to high consumption of probiotics from cultured dairy products. In recent years, Metchnikoff’s theories have been backed by strong scientific evidence, and areas with long-standing traditional consumption of cultured and fermented foods, such as Asia and Northern Europe, have taken readily to consumption of manufactured and fortified probiotics functional foods. For this reason, functional foods such as yogurts, fermented milks, cheeses and other products have long been considered a major product opportunity in Japan, Germany, France and the United Kingdom.

From 2000 to 2001, probiotic foods accounted for over $2 billion in sales in Japan, and more than $1 billion in Germany, France and the U.K. during the same year, with yogurt drinks Actimel and Yakult the top sellers. While Japan’s probiotics market is considered mature and some European markets are reaching stable growth, the U.S. market is relatively immature, as Americans have been slower to embrace probiotics use. “In the United States, we are taught that germs are bad and we go out of our way to kill them,” said Mark Brudnak, senior executive vice president of MAK Wood Inc. “However, most people don’t understand the concept of a germ. It seems very difficult for people to understand there is a very large difference between a pathogenic microorganism and a naturally occurring beneficial one. It is very difficult to get people to understand that there are some good bacteria, and you want to have them.”

Another reason the U.S. market has not reached maturity is because Americans are less likely to address issues of gut health, compared with those in many countries with high probiotics consumption. “The American consumer’s knowledge and acceptance of the direct correlation between the beneficial bacteria in their gut and overall wellness lags behind our international counterparts,” said Linda Douglas, scientific affairs manager for GTC Nutrition, manufacturers of NutraFlora® short-chain FOS (scFOS®) prebiotic fiber. Confirming this sentiment, NMI’s Health & Wellness Trends Database found only 1.2 percent of the U.S. general population has used probiotics in the past three months; 14.3 percent have heard the term probiotics and only 6.5 percent have heard the term prebiotics.

“Education is a process, and many consumers do make the connection between the beneficial cultures found in yogurt and the concept of positive bacterial colonization of the digestive system,” Douglas said. “However, since people do understand the importance of live cultures in yogurt products, the connection between bacteria and health may not be a giant leap.”

And according to market research, Americans seem willing to make that leap. More than ever, consumers are coping with increasingly stressful and active lifestyles, and are looking to foods that are convenient, flavorful, and offer health benefits beyond basic nutrition. “Foods that are easy to eat, taste good and are healthy are more realistic for the current American lifestyle and have better chances of success in this competitive market,” stated a 2001 report from market research firm MindBranch.“The benefits of eating foods with probiotics, or live microbial ingredients, have been known for a century, but demand for probiotic foods has risen precipitously in the last few decades as more consumers reach for natural, healthful products.”

And according to U.K.-based market research firm Leatherhead Food International, unlike the German and Japanese markets, the U.S. functional foods market is focused on vitamin- and mineralenriched foods, as well as high-fiber products. However, market trends forecast that probiotics foods are gaining U.S. consumer acceptance in rapidly growing numbers. Business Communications Co. Inc (BCC Inc.) estimated U.S. sales of probiotics will be $764 million in 2005, with an average annual growth rate of 7.1 percent to reach $1.1 billion by 2010. “Probiotics used in the manufacture of supplements are projected to reach $291.4 million in 2010,” wrote Rachel Agheyisi, BBC Inc. analyst. “Food applications dominate the market and sales are estimated at $498 million in 2005 and will rise at an average annual growth rate of 7 percent to $700 million in 2010. Yogurts, kefir and cultured drinks represent the major categories.”

In contrast to probiotics, prebiotics are fibers, which may make their functional nature more psychologically palatable to American consumers who recognize the importance of dietary fiber in prevention of heart disease and other ailments. Prebiotics such as inulin have been incorporated into popular food products including Kellogg’s Rice Krispies Multi-Grain breakfast cereal, and low carb energy bars. However, according to market research, American consumers are more likely to purchase prebiotic foods for their fiber content than for their gut health benefits. Therefore, education concerning the specific gut benefits of prebiotics is key.

“Most Americans are unaware of the scientific aspect of prebiotics,” according to a report by MarketResearch.com. “Products containing prebiotic ingredients, especially dietary supplements, are mostly available only in the niche market. Prebiotic ingredients in mainstream products such as yogurts, nutrition bars, and breakfast cereals are added mostly for fiber claims rather than for prebiotic claims. Consumer education coupled with scientific back up could go a long way in expanding the market.”

In the United States, there is neither a legal definition nor specific regulations regarding the marketing of probiotics or prebiotics. In contrast, in Japan probiotic foods may be granted FOSHU status by the Japanese Department of Health, making them legally recognized as foods that deliver direct health benefits and eligible to make direct health claims. Current U.S policy is that only indirect or “soft” health claims for probiotics and prebiotics are allowed by the Food and Drug Administration (FDA), such as “contains acidophilus and bifidobacteria, which are considered normal inhabitants of a healthy digestive system,” and “helps promote healthy digestion,” respectively.

Because health claims are not permitted, suppliers of proprietary probiotic strains and prebiotic products must establish product differentiation in their category to gain a competitive industry edge.

“There has been no way for consumers to distinguish between products that have undergone clinical documentation to demonstrate effect from products with only anticipated generic effect,” said Mary Arens, senior copy writer at Chr. Hansen. “On the positive side, the many products and the high volume growth offered with probiotics together with the soft health claims have helped increase consumer awareness about the relation between gut health and good bacteria.”

As increased consumer interest develops regarding the health benefits of probiotics, key issues for suppliers will be safety, viability, efficacy and taste. The therapeutic functionality and safety records of GRAS (generally recognized as safe) strains, such as L. acidophilus and B. bifidum, are welldocumented as these strains have a longhistory of human consumption. However, some newer strains on the market do not have a history of safe use in humans or animals, and novel strains should undergo strict toxicology and efficacy trials to ensure both safety and benefit to the host.

Suppliers of probiotics to dietary supplement and food companies must also have a thorough understanding of how strain characteristics affect taste, texture or appearance of foods, and their ability to survive manufacturing processes and subsequent storage. To confer beneficial effects upon the host via the GI tract, strains must be able to withstand degradation due to acid in the stomach and bile in the small intestine, and proliferate into healthy colonies inside the lower small intestine and large intestine. Because probiotics must maintain viability and potency from the date of manufacture to intestinal absorption, suppliers and manufacturers must address specific product quality issues. “To determine the manufacturing and product application properties of the strain, production pilot runs, formulations and stability studies should be done,” Arens said. “Antimicrobial activity, intestinal adhesion and other targeted in vitro assays should be run to give a good indication of the strain’s specific health benefit and mode of action.” Proper storage is crucial throughout the entire probiotic product process. Because probiotics are sensitive to degradation due to heat, light, moisture and oxygen, refrigeration is often needed to keep the bacteria viable and active.

Unlike probiotics, prebiotics are plantbased food ingredients and are generally considered safe. “Prebiotics have an excellent record of safety in all age groups and several forms of prebiotic fiber are used in infant formulas in Europe and in Japan,” Douglas said. Although considered safe, studies have shown prebiotics such as inulin and oligofructose can cause flatulence and intestinal discomfort at high doses, depending on the type of food in which they are incorporated.6 For this reason, issues regarding dosing and favorable ingredient combinations factor greatly in the manufacturing process of prebiotic functional foods.

Viability is a key product factor for probiotics, as well as a major industry concern due to recent media attention. In July 2005, Consumer Reports issued a summary of recent findings that found three of the four liquid supplements analyzed had far fewer bacterial counts than labeled, and four of the 14 supplements tested had, on average, fewer than half their claimed number of active bacteria. “Studies have shown that most probiotics on store shelves simply fail to meet label claim and many, in fact, have no viability at all by the time they reach consumers,” said Tim Gamble, vice president of sales and marketing at Nutraceutix Inc. “The final delivery form, packaging and handling of probiotics are critical factors affecting probiotic shelf-life. In order to ensure viability for the consumer, probiotics must be produced, formed and packaged in a way to heighten shelf-life and achieve gastric acid bypass, independent of the strains involved. This involves both manufacturing processes and delivery technologies.”

For the probiotic functional foods category to appeal to a broad consumer base with varying food preferences, the range of carrier foods and related technologies must be similarly expansive. For this reason, manufacturing and supplier companies are experimenting with new technologies in this arena. For example, MAK Wood Inc. is currently developing technologies to incorporate probiotics into chocolate and edible film. The company has also developed the MAKTrek Bypass Technology (MBT), a natural vegetarian product that forms a new shell when the capsule dissolves in stomach acid, protecting the probiotics until the shell reaches the intestines.

In contrast to probiotics, prebiotics are stable and can easily be incorporated into a wide range of foods. According to Douglas, prebiotics are being included into beverages, frozen dinners, processed cheeses, baked goods and convenience foods, along with the more standard methods of delivery such as yogurts, flavored milks and nutrition bars. Bulk can be an issue with formulating with some prebiotic fibers, however, and companies such as Colloides Naturels International (CNI), are making strides to overcome this formulation challenge. CNI offers a line of non-thickening prebiotic dietary fibers in its Fibregum™ line, made from acacia gum.

“Prebiotics lend themselves to nearly every food application and demand is growing as consumers begin to understand their value,” Douglas said. “Prebiotics do not have the strict temperature limitations of live cultures, which greatly expands the opportunity for including prebiotics in processed foods.”

Consumers are increasingly demanding healthy, natural, and foodbased solutions to help them enjoy healthier lifestyles, and scientific advances are spurring product innovation in the nutraceuticals industry to greater heights. In particular, the probiotics and prebiotics markets are exciting categories because they are positioned for tremendous growth due to increased interest within the United States, and cutting-edge delivery systems that will make supplementation convenient for consumers across a wide-range of food preferences. However, to reach full market potential and gain market share, suppliers must focus on safety, viability, efficacy and taste issues to differentiate their products and gain consumer confidence.

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