Probiotics are hot. Originally found primarily in dairy foods, probiotics now pop up in everything from pills to prunes. As competition mounts from other probiotic delivery vehicles, the dairy industry needs to continue to educate consumers about the benefits of dairy as a delivery vehicle for healthy bacteria.
Dairy delivers probiotics
Probiotic supplement companies aggressively advertise to consumers. Some supplements claim up to 24 months of shelf life at ambient temperatures, a sizable technological challenge compared to the short refrigerated shelf life typical for probiotics in dairy foods.
The website usprobiotics.org offers four reasons why dairy should be the preferred delivery vehicle for probiotics: “Dairy foods can protect the probiotic bacteria; refrigerated storage of dairy products helps promote probiotic stability; live cultures in dairy foods carry a positive image; and the healthful properties of probiotic bacteria blend with the healthful properties of milk products.”
“We still have a lot to learn about which probiotics are best for human health,” said Gonca Pasin, executive director of the California Dairy Research Foundation. “But we do know that those probiotics that thrive in dairy foods are the same strains that have been living with and co-evolving with humans for thousands of years. In fact, the protective effects of certain probiotics may only be activated in the presence of dairy foods. Studies on intestinal inflammation that have been conducted in mice provide evidence that specific anti-inflammatory effects of Lactobacillus casei were only noticeable when the probiotic was delivered with milk.”
Consumers are showing increased interest in fermented foods – everything from kimchee to kombucha – but they may not realize that not all fermented foods have the same health benefits. Many fermented foods do not contain live microbes at the point of sale. The processes of baking sourdough bread, filtering beer or pasteurizing sauerkraut will kill or remove live bacteria.
“Not all fermented foods contain probiotics. They may. But in order to be a probiotic, a live microbe must be studied and shown to have health benefits. Many fermented foods do not reach that level of evidence,” explained Mary Ellen Sanders of Dairy and Food Culture Technologies, Centennial, Colo., in a recent post.
Single vs. multiple strain
Clinical trials continue to document the health benefits of probiotics. Much probiotic research has focused on the benefits of a specific single strain of bacteria, yet many yogurts and kefir contain multiple species. Which is better?
In 2014, the International Scientific Association for Probiotics and Prebiotics issued an expert consensus report on the appropriate used of the term probiotic. Some strains produce “rare” probiotic effects. Examples might include claims about the production and delivery of neuroactive substances including serotonin to improve mood, or claims about a reduction in body fat mass and trunk fat to promote weight management. Such claims would require extensive human trials and be strain and dosage specific.
A clinical trial published in 2016 documented the benefits of 10 billion CFU of Bifidobacterium lactis B420, a culture strain recently launched by DuPont. “Howaru Shape helps consumers manage their waistline and is a great complement to dairy products, as it can boost the already strong consumer appeal that dairy protein has for weight management,” said Anders Gron Norager, the director of Global Probiotics at DuPont Nutrition & Health, Copenhagen, Denmark.
A 2011 review in the European Journal of Nutrition determined that of 16 studies comparing the efficacy of multi-strain probiotics to their component strains individually, 75% showed the blends to be more effective. The study concluded that “Mixtures of probiotics had beneficial effects on the end points including irritable bowel syndrome and gut function, diarrhea, atopic disease, immune function and respiratory tract infections, gut microbiota modulation, inflammatory bowel disease and treatment of Helicobacter pylori infection.”
Are regular yogurt starter cultures probiotic? Yogurts with live cultures do improve lactose digestion, a benefit that yogurt producers should tout. The World Gastroenterology Organization states, “Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus improve lactose digestion and reduce symptoms related to lactose intolerance.”
The recommended dosage is at least 108 CFU of each strain per gram of product. This benefit was confirmed in a number of controlled studies with individuals consuming yogurt with live cultures.
Probiotics have a bright future in dairy products. In order to maintain the integrity of dairy as a delivery vehicle, manufacturers should clearly and accurately document the health benefits of their probiotic product. They should also ensure that the product meets the documented dosage to deliver that benefit at the end of the stated shelf life.