Out of thirteen products ConsumerLab.com selected for testing, only two were found to accurately list the number of cells viable at the time of purchase. The actual amount of viable probiotic cells in a daily serving ranged from over ten billion to less than one hundred million -- more than a 10,000% difference. Despite providing fewer viable organisms than one might expected, most products yielded at least one billion organisms, an amount that may provide some benefit.
Probiotics help re-populate the gut with live beneficial bacteria such as Lactobacillus acidophilus, Lactobacillus GG, Bifidobacterium infantis and others, as well as specific yeast such as Saccharomyces boulardii. Studies have shown some probiotic strains reduce symptoms of irritable bowel syndrome (IBS) and reduce diarrhea caused by viral infection or antibiotics. They may also help treat H. pylori infection (a causative agent of stomach ulcers) and vaginal bacterial infection, among other uses. Sales of probiotic supplements grew 16.3% in 2008 to reach $425 million in the U.S. according to Nutrition Business Journal.
ConsumerLab.com purchased the products as a consumer would, cultured them to determine the number of viable cells, and compared the amounts found with those listed on product labels. ConsumerLab.com found many products to qualify the listed amount of cells with the statement "at time of manufacture," an unusual practice because supplements are normally expected to provide at least 100% of their listed ingredients until the expiration date. One probiotic was found to take both approaches, promoting "12 BILLION CELLS" per capsule on its front label (footnoted as being "at date of manufacture"), while its supplement facts panel guaranteed an amount through expiration that was actually 80% lower.
The study also evaluated pet probiotics. Across the products, very large differences were noted in the number of cells in the suggested daily dosage.
"Consumers should keep in mind that a large percentage of organisms in a probiotic supplement may die before a product is even purchased and labels can be misleading or incorrect," said Tod Cooperman, MD, President of ConsumerLab.com. "Many products start with several billion viable cells, but there may or may not be a sufficient number of viable cells remaining at time of use to be beneficial." Dr. Cooperman advised using products known to deliver an adult daily dose of at least one billion viable cells or an amount proven to be clinically effective for that strain. He suggested that products be stored in sealed containers out of heat, light, and humidity. In addition, if a label indicates that a product should refrigerated (not just after opening) it should be sold in a refrigerated condition and kept that way.
The Product Review of Probiotic Supplements is found at http://www.consumerlab.com/reviews//probiotics/. It provides findings for fourteen products that ConsumerLab.com selected for testing and thirteen additional products that passed the same testing through ConsumerLab.com's Voluntary Certification Program. It also includes information about two products similar to those tested. Brands included in the report are Advocare, Align, Ark Naturals, Culturelle, DDS, Dr. D, FloraStor, GNC, i-Flora, Jarrow Formulas, Kashi, Kyo-Dophilus, Metagenics, Nature Made, Nature's Bounty, Nature's Secret, New Chapter, Nutri-Vet, Optimal Pet, Phillips Colon Health, Proviable (Nutramax), Puritan's Pride, Solgar, Swiss Natural, Udo's Choice (Flora), Weil, and Vitamin World. In addition to providing test results, the report also reviews clinical information regarding probiotics.
ConsumerLab.com is a leading provider of consumer information and independent evaluations of products that affect health and nutrition. Reviews of other popular types of supplements are available from www.consumerlab.com. Subscription to ConsumerLab.com is available online. The company is privately held and based in Westchester, New York. It has no ownership from, or interest in, companies that manufacture, distribute, or sell consumer products.