Delivering Probiotics

Probiotic-enhanced foods and beverages are rolling out at record rates in the United States. From boosting immunity to aiding gastrointestinal ailments, products formulated with these “good-for-you” microorganisms claim to offer potential benefits for a range of health conditions.

“This is a particularly important time in the evolution of probiotic research,” says Gregor Reid, researcher, Canadian R&D Centre for Probiotics, London, Ontario. “There has been strong growth in foods containing probiotics, and a number of them are supported with clinical studies showing health benefits.”

Yogurt and fermented milks remain the most-popular delivery vehicles for probiotics. However, other food matrices—from breakfast cereal to ketchup—are also claiming to be formulated with probiotic cultures. Many in the scientific community question the accuracy of calling these foods probiotic.

“A potential major problem for probiotics is the misuse of the term,” says Reid. “This can arise from products being poorly manufactured or being referred to as probiotic without any relevant documentation. The net effect, deleterious to the overall field of probiotics, might be that such products are found to be ineffective, when in fact they were not even probiotic in the first place.”

Mary Ellen Sanders, consultant, Dairy & Food Culture Technologies, Centennial, CO, says, “Strain-specific clinical data demonstrating health benefits, and formulation of products with the effective dose, is essential for the future of credible probiotic foods and beverages.”

Reid concurs, adding, “By uncovering how probiotic interventions function in vivo, it will be possible to further expand applications that improve general health, and in some cases provide adjunctive anti-disease benefits.

“Further, it is important that probiotic products meet appropriate international standards and contain appropriately speciated and characterized organisms,” Reid continues. Thus, it is the responsibility of food and beverage manufacturers, probiotic marketers and scientists to use the term probiotic responsibly.

Qualifying as probiotic

The term probiotic is not legally defined or regulated in the United States, and thus the industry must self-regulate. International guidelines come from the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO). The guidelines define probiotics as “live microorganisms which, when administered in adequate amounts, confer a health benefit on the host.” The complete FAO/WHO “Guidelines for the Evaluation of Probiotics in Food” can be found at who.int/foodsafety/fs_management/en/probiotic_guidelines.pdf.

Doses, dosages and efficacy

“Many of the probiotics strains that are in the global market are of human origin,” says Mirjana Curic-Bawden, senior scientist, Chr. Hansen, Inc., Milwaukee, WI.

However, according to Sanders, no evidence indicates human origin is an important issue.

“Probiotic efficacy is strain-specific and dependent upon the type of effect,” says Mike Bush, vice president of business development, Ganeden Biotech, Inc., Mayfield Heights, OH. “While one studied effect may require more cells per day for a longer period of time, other effects may require shorter periods of consumption of fewer cells. There is no set number, as some strains have been studied using millions of cells per day while others require trillions.” It is best to work with the manufacturer of specific strains to learn at what levels their organisms have been studied and clinically proven effective.

“Typically, with the cultures from Danisco, this is at or above one to five billion cells per day, again depending on the end benefit needed,” says Gregory Leyer, probiotic technical director, Danisco-Cultures Division, Madison, WI.

“The documented dose is usually delivered in one serving,” Curic-Bawden says. An alternative is to indicate the number of servings needed to deliver a daily dose. Also, to be effective, probiotics must be consumed on a regular basis.

“The efficacy of probiotics depends on a multitude of factors, such as whether or not that strain can survive the manufacturing process, the shelf life of the product and the acid in the stomach to colonize the intestines, as well as where the bacteria optimally grows,” says Bush.

Leyer adds: “As the composition of foods and beverages are varied, so to are the optimal environments that contribute to maintaining strain viability and, hence, efficacy. Within food systems that fall on the lower end of the water activity scale (i.e., dry beverage mixes, nutritional bars, chocolates, etc.), the largest impact on stability will be the water activity of that system (the lower the better), the storage temperature (the lower the better) and the time expected for shelf life (the shorter the better). In these systems where the probiotic cells are not active, the secret is keeping them dormant by keeping them away from water.

“In systems on the higher end of the water-activity scale, such as fluid beverages and yogurts, the probiotic organism is actively metabolizing, and the key to keeping the organism viable is dependent on the attributes of the food (namely pH and the impact of other ingredients) and the attributes of the probiotic organism (pH tolerance, etc.),” continues Leyer. “In acidic beverages, most organisms will do much better at pH 4 and above.”

Traditionally, probiotics have been delivered in cultured dairy products, because probiotics survive very well in the refrigerated confines of short-shelf-life dairy products. “With the introduction of next-generation probiotics that do not require refrigeration, the options for food delivery vehicles are greatly expanding,” says Bush. “Food companies can now produce products that deliver comparable, or greater, numbers of cells to the gut than yogurt in nonrefrigerated, longer-shelf-life products with a variety of pH ranges and water-activity levels.”

Ask the right questions

A handful of microorganisms qualify as probiotics, according to FAO/WHO. It is up to the food formulator to obtain the necessary efficacy data from the probiotic supplier.

For example, “Bifidobacterium animalis ssp. lactis is scientifically documented to positively affect the gastrointestinal tract when at least 1E+09 CFUs are consumed daily,” Curic-Bawden says. “It has also been shown to positively affect immunity.”

Danisco’s range of probiotics includes highly documented, health-enhancing cultures. Bifidobacterium and Lactobacillus rhamnosus, for example, have immune-modulating properties, and dophilus contributes to overall gut health. “These probiotic cultures have been proven efficacious in gold-standard, human clinical studies,” Leyer explains.

“Traditional probiotic strains, such as Lactobacillus and Bifidobacterium, have very low survival levels on the shelf, and application options are very limited, due to the very high levels of loss in even the most-gentle food-manufacturing process,” Bush says.

“For any probiotic to have a value to the consumer, it must survive the manufacturing process, be stable during the shelf life of the product and ultimately survive passage through the digestive system so they can colonize in the intestines,” Bush continues. “The spore-forming nature of our patented strain of Bacillus coagulans allows for the organism to remain in a dormant state during all of these stages to ultimately survive to proliferate in the intestines. It has the ability to survive through both high and low temperatures, high pressure and shear, and a variety of pH ranges and water activities.” Further, he notes, it is stable in a large variety of manufacturing processes that would ordinarily kill most other probiotic organisms, has up to a two-year shelf life and can endure stomach acids to proliferate in the small intestine.

“To attain more-widespread credibility amongst the scientific and clinical communities, products must contain speciated strains, sufficiently viable at end of shelf life, and with appropriate label claims,” Reid says. “Further, studies are needed to assess the contributions that different delivery vehicles make to the efficacy of products.”

Donna Berry, president of Chicago-based Dairy & Food Communications, Inc., a network of professionals in business-to-business technical and trade communications, has been writing about product development and marketing for 13 years. Prior to that, she worked for Kraft Foods in the natural-cheese division. She has a B.S. in food science from the University of Illinois in Urbana-Champaign. She can be reached at [email protected].