BEVERLY HILLS, CALIF. — The Food and Drug Administration provides little regulation of probiotic products, and those products available to the consumer vary greatly in quality and the level of evidence supporting their label claims, Lynne V. McFarland, Ph.D., said at the International Probiotic Association World Congress.
Even consumers who make concerted efforts to research probiotic products may come up short, said Dr. McFarland of the Veterans Affairs Puget Sound Healthcare System, Seattle. “There are so many different probiotic products, and the diversity of quality can be all the way from fine pharmaceutical manufacturers to [someone who makes it] in his bathtub.”
Dr. McFarland recently tried to track down the contents and evidence base behind three probiotic products brought to her by patients. Using information from the manufacturers' Web sites—and a few persistent phone calls—she sought details on VitAdvance Flat Stomach capsules, Activia yogurt, and Culturelle capsules.
▸ VitAdvance Flat Stomach, manufactured by Avon Products Inc., has promotional literature that reads, in part, “Battling belly bulge means staying away from the bar and picking up a barbell. But a new pill is promising to beat bloat and tighten the tummy.”
On the manufacturer's Web site, Dr. McFarland found no information on the probiotic species in the capsules, the dose, or the evidence for the maker's claims. After several phone calls, she spoke to a technician who told her the product contains Lactobacillus acidophilus, although he was unable to determine the dosage.
The flat-stomach claim appears to be based on a single randomized controlled trial with 18 women with irritable bowel syndrome (IBS). In that trial, the L. acidophilus had no effect on global IBS symptoms, cramping, or flatulence, but seemed to reduce bloating.
“They have one little piece of the significant evidence, and they built their whole product around this, and called it Flat Stomach,” Dr. McFarland said. “This [should not be allowed] to happen.”
▸ Activia yogurt, made by Dannon Co., claims to, “help with the slow intestinal transit and contains a unique culture—Bifidus regularis.” There is no recognized organism correctly classified as Bifidus regularis. The health professional's portion of the product's Web site reveals that this is a trade name for Bifidobacterium animalis strain DN-173 010, but it includes no information on dose.
However, the Web site does have information on three randomized clinical trials involving a total of 113 normal volunteers showing a 9-hour reduction in transit time. Dr. McFarland pointed out that these normal volunteers are not likely to be representative of patients with constipation, and the company mentioned no trials in constipated patients.
The company recommends consumers eat Activia yogurt daily, although there is no mention of long-term studies showing the value of daily intake.
▸ Culturelle, manufactured by Amerifit Brands Inc., has the best evidence base of the three products in support of its claims. The label says that the product “maintains a healthy intestinal tract,” and it also includes the species (Lactobacillus rhamnosus GG), the dose (1010 live organisms per capsule), and an expiration date.
The Web site lists information on 42 randomized clinical trials, 25 of which had a positive effect directly related to the label's health claim. “This is what every Web site for a probiotic product should look like,” Dr. McFarland said.
Dr. McFarland acknowledged serving on the speakers bureau of Klaire Laboratories and Biocodex Inc.