All probiotics are not created equal. That’s the message researchers are trying to get across to the public as the market for these beneficial organisms reaches unprecedented highs.
“The biggest mistake made at the commercial level is that people say, ‘There’s a lot of information out there about probiotics in general, so I should buy something that says probiotic on it,’” says microbiologist Mary Ellen Sanders, PhD, executive director of the International Scientific Association for Probiotics and Prebiotics. “The research has clearly shown that not all probiotics function the same way.”
Roughly a century after Russian Nobel Laureate Elie Metchnikoff first suggested that ingesting certain bacteria could promote health, the concept has taken off over the past decade, with consumers (excluding Whole Foods Market and Walmart shoppers) spending $1.2 billion on probiotic foods and supplements from September 2009 to September 2010—up 27 percent from the previous 52-week period, according to SPINS, a Schaumburg, Ill.-based market research company. Probiotic supplements sales alone topped $530 million in 2009, Nutrition Business Journal reports. And according to the Global New Products Database from Chicago-based market research firm Mintel, food manufacturers launched 521 new foods and drinks with functional or digestive claims between 2007 and September 2010. Meanwhile, the number of human trials has quadrupled since 2000, with studies showing probiotics can prevent or treat gastrointestinal problems, eczema, flu-like symptoms and more.
But the surge in awareness has also sparked a flood of products that fail to meet the World Health Organization’s definition of probiotics: “live microorganisms, which when administered in adequate amounts, confer a health benefit on the host.”
“There is nothing in the scientific literature about many of the strains being sold,” says Bob Hutkins, PhD, professor of food science at the University of Nebraska.
Amid a dizzying array of options, how can retailers stock probiotic products that work, and be sure they are pointing customers toward the proper formulations?
Know your strains
“Lesson number one for retailers: Strains matter,” says Hutkins, noting that different strains (even those within the same genus and species) trigger different physiological processes and address different conditions. “Some strains have scientific evidence to support a specific health benefit, and those are the ones consumers should seek.”
In general, probiotics work by helping to maintain or restore naturally occurring healthy gut bacteria, which can be thrown off by stress, illness or prescription antibiotics.
However, strains in the genus Lactobacillus are more commonly associated with bolstering immunity and fending off immune-related conditions (like allergies), while strains in the Bifidobacteria genus are linked to digestive health, explains Gary Huffnagle, PhD, author of The Probiotics Revolution (Bantam, 2007). He says healthy people interested in probiotics for general health maintenance should look for food or supplements containing live cultures of both Lactobacillus and Bifidobacteria, and shoot for 1 billion to 5 billion colony-forming units per day.
But seeking probiotics to prevent or treat certain conditions is trickier.
Probiotics to prevent or treat certain conditions
Parents hoping to prevent allergies in children may want a product containing Lactobacillus rhamnosus GG (found in Culturelle supplements and some Dannon yogurt products, to name a few). “This is one of the most extensively studied strains for that purpose,” says Michael Cabana, MD, a pediatrician and probiotics researcher at the University of California, San Francisco. One sentinel study of 132 children, published in the journal Lancet in 2001, found that newborns given Lactobacillus rhamnosus GG daily until they were 6 months old (and whose mothers took it while pregnant) had half the incidence of eczema (an early sign of allergies and asthma) as the placebo group by age 2. The GG strain has also been shown to prevent antibiotic-induced diarrhea and quell infection-caused diarrhea.
Lactobacillus rhamnosus GR1 (found in Jarrow’s Fem-Dophilus and other supplements) has been shown in several clinical trials to prevent urinary tract and vaginal infections.
For general immune support, Lactobacillus acidophilus NCFM (marketed by ingredient supplier Danisco and found in supplements and foods) and Lactobacillus casei DN-114 001 (found in DanActive cultured dairy drink) have both shown great promise. According to a study of 326 children published in the journal Pediatrics in 2009, those who took NCFM twice daily for six months had significantly fewer flu symptoms, took fewer antibiotics and missed fewer school days. And a 2010 study of 638 children, published in the European Journal of Clinical Nutrition, found that those who took casei DN-114 001 had 19 percent fewer colds and 24 percent fewer cases of diarrhea and vomiting.
For digestive problems, Bifidobacterium infantis 35624 (found in Procter & Gamble’s Align probiotic supplement) has proven effective in several human trials. A 2007 study of 362 women with irritable bowel syndrome found that those who took B. infantis 35624 for four weeks had significant improvement in symptoms compared with taking a placebo. Another study, currently under way at Harvard University, is examining the effects of Ganeden BC30 (Bacillus coagulans GB1-30, 6086) on people diagnosed with both irritable bowel syndrome and major depressive disorder.
Meanwhile, many companies have developed products that contain multiple scientifically tested strains that address different conditions. For instance, American Health’s new Probiotic CD (for people with chronic digestive problems like IBS) contains 10 different strains of Lactobacillus and Bifidobacteria, delivered in a time-release fashion that carries microbes to both the small and large intestines without being degraded by stomach acid.
Should retailers be expected to memorize every probiotic strain and know what each does? Probably not, Hutkins and Sanders say. But each product the store carries should show the specific genus, species and strain names either on the label or at a manufacturer’s website, so that retailers—and their customers—can look up the health benefits associated with that strain.
“The bottom line: If a product doesn’t indicate the strain, I wouldn’t carry it,” Sanders says. If not indicated, “the manufacturer either doesn’t care which strain is used, or they don’t have data on why it is healthy.”
Cabana says products should also state clearly on the label how many CFUs of probiotics are present per dose in supplements or per serving in food. In addition, it’s important that the dosages they contain are active through the end of the products’ shelf life and have been shown in clinical trials to be effective. (While dosages vary considerably from strain to strain, most pediatric studies have used 3 billion to 5 billion CFUs per day). “Just because I sprinkle a few bacteria on an energy bar doesn’t make it a probiotic,” Cabana says.
In the end, even the most carefully selected, high-quality strain may not work for everyone, because “we all have a unique flora that we carry within us,” Huffnagle says.