An appetite for bacteria?
Have you eaten any good bacteria lately?
Given the E. coli-in-spinach nightmare, that may seem like an odd question.
But, in fact, foods and supplements containing probiotics — living microorganisms that, in sufficient doses, are thought to yield health benefits — are a growing part of the U.S. diet. And manufacturers are making a big new push to get them into the carts of mainstream consumers.
Advertising Age reports that Dannon Co. is so encouraged by sales of its probiotic Activia yogurt, touted as a digestive aide, that it plans to launch or expand marketing for other specialized yogurts, including its DanActive drink, promoted as an immunity booster.
Meanwhile, kefir, a fermented-milk drink, has gotten a marketing makeover as a line of multiflavored probiotic beverages sold by Lifeway Foods. And pills and potions containing probiotics are among the most numerous — and expensive — supplements sold at stores such as Whole Foods.
"The buzz about probiotics has become a roar," said a report in June from the American Academy of Microbiology.
Can consumers believe the hype?
In this case, the answer might be yes — though caveats apply.
Probiotics have been under scientific scrutiny for years. The research is based on a growing appreciation that a healthy human body relies on armies of "friendly" bacteria. The good bugs keep bad bugs in check and may perform other functions essential to a healthy gut and immune system. But the balance of bacteria can be thrown off by a number of factors, including the use of antibiotics (which kill both good and bad bugs), a poor diet, stress and infection.
So a dose of the right bacteria at the right time might well come to the rescue of people who have ailments such as lactose intolerance, diarrhea and irritable bowel syndrome.
One Swedish study showed that employees who received a daily dose of Lactobacillus reuteri had fewer sick days than those who got a placebo. A Finnish study found that infants at high risk for allergies because of family history were less likely to develop them if their mothers ingested certain bacteria during pregnancy and the newborns got doses for six months. Meanwhile, very preliminary research suggests probiotics might play a role in preventing tooth decay, lowering blood pressure and cholesterol, or even preventing some cancers.
"The science in many cases is still evolving," says Mary Ellen Sanders, a microbiologist in Colorado who advises probiotic marketers.
While the evolution continues, consumers should be aware that:
• Probiotic foods and supplements are not considered drugs, so the health claims on their labels have not been reviewed by the U.S. Food and Drug Administration.
• Manufacturers do not have to prove that their products contain the types or amounts of bacteria claimed on their labels — or that the bacteria survive long enough to do consumers any good.
• Different strains of the same bacteria can have very different effects.
The report from the microbiology academy concluded: "At present, the quality of probiotics available to consumers is unreliable." It also cautioned that some products might not be safe for certain consumers, especially those with impaired immune systems.
Given the doubts, "it's just not clear that these newer products have any advantage over good old-fashioned yogurt," says David Grotto, a Chicago area nutrition consultant and spokesman for the American Dietetic Association.
But others are more enthusiastic. Probiotics to prevent and treat allergies and infections in children "have great potential value," says Allan Walker, director of the division of nutrition at Harvard Medical School. He has consulted for probiotic manufacturers.
Walker says most pediatricians know little about probiotics but are getting a lot of questions about them from parents. For now, he says, the science does not support any broad recommendations, but his general advice is to buy only from well-known manufacturers who would have a lot to lose if their products eventually were found to be useless or unsafe.