Probiotics have been making headlines in a number of peer-reviewed scientific journals. What’s important to note is how researchers identify strains and viable cell counts - something U.S. dairy marketers could use as an example when they promote the benefits of consuming probiotic-enhanced dairy foods.
A daily supplement ofLactobacillus acidophilus NCFM andBifidobacteriumlactisBi-07 strains has been shown to reduce the incidence of cold and flu-like symptoms in children by 50%, according to a study published inPediatrics(124: e172-e179). A combination of the two strains was linked to reductions in fever incidence by 73%, a reduction in the occurrence of runny noses by 59% and drop in the incidence of coughing by 62%. According to the study,L. acidophilusNCFM alone was effective; however, a trend for a broader protective effect was observed with the combination ofL. acidophilus NCFM andB. lactis Bi-07.
Commenting on the mechanism, the researchers said that an immune-enhancing effect was the “likely explanation, because numerous studies with various probiotic bacteria have demonstrated their ability to modulate immune responses through interactions with toll-like receptors.” Furthermore, they note that part of the rationale behind the strain choice for this study was the strains’ ability to stimulate cells called dendritic cells, which play a role in immune systems function.
Probiotic viability was studied by Brazilian scientists with results recently published in theInternational Journal of Dairy Technology (62:397-404). This study investigated the viability of three probiotic bacteria -Lactobacillus acidophilus LA5,Lactobacillus rhamnosus LBA andBifidobacterium animalis ssp. lactisBL-04 - in milk fermented with standard yogurt cultures -Lactobacillus delbrueckii ssp. bulgaricusLB340 and Streptococcus thermophilus. Each probiotic strain was grown separately with the standard yogurt cultures and in different combinations.
The researchers concluded that blends affected fermentation times, pH and firmness during refrigerated storage. The product made with the standard yogurt cultures plus B. animalis ssp. lactis and L. rhamnosus had counts of viable cells at the end of shelf life that met the minimum required to achieve probiotic effect. However,L. acidophilusandL. delbrueckii ssp. bulgaricus were inhibited.
In a separate study published in the same edition of theInternational Journal of Dairy Technology(62:444-451), scientists investigated using probiotic bacteria in the production of ice cream. Different cream levels (5% and 10%) and different strains of probiotic bacteria (L. acidophilusandB. bifidum) were used in ice cream production to determine their effects on the quality of the ice creams in each group.
During storage at time intervals up to 90 days,L. acidophilusandB. bifidum counts, and sensory analyses were performed. The results obtained at the end of storage demonstrated that the counts ofL. acidophilusandB. bifidum decreased during frozen storage, but all types of ice cream samples seemed to preserve their probiotic property even after 90 days. The researchers concluded that although sensory scores of probiotic ice cream samples reduced during this time, they rated as “tasty” for both cream levels throughout storage.
At the IFT 2009 Annual Meeting and Food Expo, Dairy Management Inc., Rosemont, Ill., sampled an English toffee reduced-fat ice cream with probiotics for digestive health. The formulation includes theL. acidophilus NCFM strain. According to DMI, post-production viable cell count was quantified as 5x108 bacteria per half-cup serving.
All this probiotic research is great - but do Americans finally understand what they are all about?
What Americans know about probiotics
The good news is that research indicates that the majority of Americans finally understand how consuming probiotics can make a positive contribution to health.Washington, D.C.-based International Food Information Council commissioned Cogent Research, Cambridge, Mass., to conduct the 2009Functional Foods/Foods for Health Consumer Trending Survey, a quantitative study to measure Americans’ attitudes toward, awareness of and interest in functional foods. Between May 11 and 20, 1,005 U.S. adults 18 years and older were randomly invited to participate in a 20-minute Web-based survey (see chart).
Consumers were asked, on an aided basis, whether they are aware of certain food components, their corresponding food sources and their associated health benefits. The most recognizable food/health associations continue to be those related to bone health, cardiovascular disease, cancer and benefits associated with fiber. With the exception of a few associations, awareness increased significantly since 2007. For example, two key associations included probiotics for maintaining healthy digestive and immune systems (72% vs. 58% in 2007 and 71% vs. 54% in 2007, respectively).
Of the 72% of consumers aware of the relationship of probiotics and a healthy digestive system, 38% said they are already consuming probiotics for this reason, while 47% are likely or somewhat likely to consume. Of the 71% aware of how probiotics maintain a healthy immune system, 41% said they are already consuming probiotics for this reason, while 42% are likely of somewhat likely to consume.
Research from independent market analyst Datamonitor, London, suggests that American’s relationship with probiotics is at its infancy. Indeed, manufacturers are responding to consumer interest by incorporating probiotics into more foods that people eat every day.
“People find these products appealing and, more importantly, they like how they taste,” says Mark Whalley, consumer markets analyst at Datamonitor. “Digestive health has strong links with immunity health, which means that consumers feel better after eating their probiotic yogurts. This is what keeps them coming back for more.
“The real success of these products has been the way in which consumers have adopted them for a ‘daily dosing’ routine.”
Probiotic claims in Europe
The European Food Safety Authority is making it very difficult for marketers of probiotics to make health claims. EFSA emphasizes the importance of accurately demonstrating nutritional and physiological effects with “appropriate outcome measures of that claimed effect.”Claims must be sufficiently defined and strictly related to the evidence presented.
“The claimed effect needs to be specific enough to be testable and measurable by generally accepted methods,” according to EFSA. “For example, ‘gut health’ is too general (unclear what measure can be used) but ‘transit time’ is specific (measurable by generally accepted methods).”
EFSA emphasizes the importance of targeted studies carried out on the food/constituent; the importance of human data; conditions of use; relevant study groups and usable animal models. “As human data are central for the substantiation of a claim, particular attention should be given to ensuring that the human studies presented are pertinent to the claim,” EFSA states.
Back in the States, Americans are embracing probiotics and, for the most part, are not cynical about the claims being made - yet. In fact, only a minority (14.4%) say they firmly disbelieve the claims that these products make, according to Datamonitor.
