Probiotics: They Sound Good, but How Friendly Are They?
What exactly is going on in those Activia ads, anyway?
One minute actress Jamie Lee Curtis is talking. Then comes a graphic of a female-looking abdomen with a bunch of yellow dots swarming around in the middle. As 14 calendar pages flip, the dots arrange themselves in the shape of a downward-pointing arrow. A mysterious orb appears at the base of that arrow, and then it follows the arrow as it moves toward the bottom of the screen and disappears.
This is how vendors such as Dannon have to sell the busy bacteria we call probiotics -- euphemistically dodging unlovely images such as what happens when we get over being constipated and carefully avoiding making medical claims.
Because, for all their purported benefits, probiotics are not medicine. They are, according to the World Health Organization, "live microorganisms which when administered in adequate amounts confer a health benefit on the host." The term literally means something akin to "good for life" and is often oversimplified as referring to "friendly bacteria." They occur naturally in some foods, notably yogurt and other dairy products, and are being added to other foods and offered as supplements.
Discovered more than a century ago by the Russian scientist Ilya Mechnikov, probiotics are the stars of the functional-food realm, wherein foods promise to do things beyond simply tasting good and providing nutrients. While different strains in different quantities and formulations may have varying effects, the general idea is that they help repopulate colonies of "good" bacteria in the gut, undermining the effects of potentially harmful "bad" bacteria.
Probiotics are also under intense scientific scrutiny to assess their utility in treating and preventing illness. The current issue of the journal Nutrition in Clinical Practice, for instance, features several articles about probiotics' application in a number of clinical settings, from preventing diarrhea to improving the health of children and critically ill adults. While probiotics -- in food, capsule or powder form, depending on the study -- show promise in those areas, each of the studies concludes that not enough is yet known for them to become a standard treatment.
As Mary Ellen Sanders, an oft-quoted probiotics expert, notes, there are no probiotic drugs approved for any use in the United States. That suggests that if you're taking a probiotic supplement or eating yogurt or probiotic-infused cheese to address a specific malady, you're going beyond the pale of current medical understanding.
"There's a disconnect between the body of literature and what's actually happening in the marketplace, in foods and supplements," Sanders says.
That disconnect plays out in the way companies talk about their probiotic products. Dannon says Activia can "shorten transit time," which has nothing to do with improving your morning commute. Transit time is how long it takes food to move through your digestive system; shortening it is a loose euphemism for clearing up constipation.
Activia's proprietary ingredient, Bifidus Regularis, may indeed shorten transit time or, as the small print in the TV ad says, help "relieve temporary symptoms of irregularity" or, as the voiceover says, "regulate the digestive system in two weeks."
But a yogurt manufacturer can't come right out and say its product relieves constipation because constipation is a medical condition, and anything that would cure that condition would be seen -- and regulated -- by the Food and Drug Administration as a drug. That would entail rigorous review of the science behind the claim, far more than is required when a manufacturer simply says a food product may "shorten transit time."
Which is not to say that Activia or other dairy products containing live cultures aren't good for you; those probiotics may in fact confer health benefits, and Dannon's Web site lists some studies suggesting probiotics may help promote digestive, immune-system and oral health.