New Report Claims That Many Probiotics Provide Fewer Live Cells Than Listed on Labels

Americans are spending more and more dollars each year on probiotic supplements, or so-called "friendly" bacteria. Studies have shown that probiotics—which you might purchase in the form of yogurt, capsules, miso, beverages, or powders—can treat a host of conditions, including irritable bowel syndrome, diarrhea caused by viral infection or antibiotics, vaginal yeast infections, hypertension, the common cold, and even acne. Over the past decade, consumer sales of probiotics in the U.S. have nearly quadrupled (growing from $115 million in 1998 to $425 million in 2008), according to Nutrition Business Journal.

But, according to a report released today, many of the most popular probiotic supplements don't contain the amount of live bacteria listed on their labels. ConsumerLab, a private company that tests health and nutritional products at independent labs across the country, found that at the time a consumer buys a probiotic, it may contain as little as 10 to 58 percent of the amount of viable organisms listed on the label. "It's shocking how many products really don't have what they claim on their labels," says Tod Cooperman, the president of ConsumerLab. "The buyer has to be careful."

ConsumerLab purchased the probiotics as a consumer would, cultured the products to determine the number of viable cells in them, and compared the results to the amounts listed on the product labels. The company sent any product that did not contain the amount of live cells listed on the label to a second lab for additional testing. "We're absolutely certain about what we found," Cooperman says. Despite the misleading numbers, most products contained at least one billion organisms, which is probably enough to provide some—although not necessarily optimal—benefit, according to Cooperman.

In that sense, The ConsumerLab report reveals false marketing rather than ineffective products. Mary Ellen Sanders, a probiotics expert and microbiologist unaffiliated with ConsumerLab, says that although the majority of products on the market need between 1 and 10 billion live cells to work, there's no benchmark number that researchers can use. "If you do a study that shows that 100 million causes a health effect, then that's an adequate dose," she says.

Consumers should therefore consider more than just the number of live cells in a given product. What really matters is whether or not there's evidence that a probiotic supplement can actually reduce or treat the buyer's specific symptoms. "The best products on the market are the ones that have been tested in human studies and have been shown to have a benefit," Sanders says. Still, she adds, even if people only need a small percentage of the live cells listed on a label to see a health benefit, companies should be forthcoming about what's actually in their products.

And numerous products that ConsumerLab tested contained misleading labels. Nature's Secret Ultimate Probiotics claimed to contain 4 billion cells from 17 different strains per tablet at the time of manufacture, but testing found 520 million viable cells, just 13 percent of the original amount. Swiss Natural Sources "5" Strain Dophilus claimed to contain 6 billion cells from five different strains per capsule at the time of manufacture, but testing found just 0.8 billion viable cells, or 13 percent of that amount.

Mary Jane Kordahi, the vice president of marketing at Irwin Naturals (which makes Nature's Secret Ultimate Probiotics), says that since her company specifies on its label that the product contains 4 billion cells only at the time of manufacture, the marketing is "not deceptive." She says that during the first six months of shelf life, a large percentage of the live cultures begin to die (although she admits that far more than 13 percent should survive). Shipping and storage conditions might have contributed to the high death rate in the particular bottles that ConsumerLab chose for testing, she says. Swiss Herbal Remedies did not respond to a request for comment about its "5" Strain Dophilus.

The number of live cells in Dr. D Chocolate-Flavored Probiotics was particularly low. The pediatric product claimed to provide 1.3 billion cells per chocolate "bear," but testing found only 91 million viable cells—or a mere 7 percent of that amount. Stefan Friedman, a spokesman for Dr. D, said in a written statement that typical tests wouldn't take into account that the live cultures in this particular product were encapsulated "to ensure safe delivery of the bacteria to the intestine." Tests need to "break" the encapsulation, says Friedman, in order to find the live bacteria. He claims that the 7 percent of bacteria found by the two independent laboratories was actually "extra bacteria that was not encapsulated completely and was visible during the test."

But Cooperman says that ConsumerLab took encapsulation methods into account. "Prior to culturing each product, each was put through a device in which it was mixed for approximately an hour in warm agar, activating any bacteria, whether or not encapsulated," he says. Indeed, other encapsulated products, such as Jarrow femdophilus, were found to contain 100 percent of their listed bacteria. "We would not have had such results if encapsulation caused a problem," Cooperman says.

Sanders says that it can sometimes be difficult to get accurate results when testing probiotics. "There are a variety of different types of microbes that are used in probiotics, and different ones grow up better under different conditions," she says. "You need to know the microbes you're working with in order to know the best way to count what's there."

Unfortunately, it's not easy for consumers to determine which products they can trust. Sanders says that companies use the term "probiotics," which doesn't have a legal definition, quite loosely. For now, Sanders recommends that buyers call the manufacturer (or visit the company's Web sites) to make sure there's scientific evidence that a given product actually works.

The highest quality probiotics that ConsumerLab tested included Advocare Probiotic Restore, GNC Nature Brand Best Super Acidophilus, and Jarrow Formulas Jarro-Dophilus. For the full report, click here.