JANUARY 13, 2009
Bug Crazy: Assessing The Benefits of Probiotics
By LAURA JOHANNES
WSJ
Bacteria are everywhere, and in the view of many people that's a good thing. Many medical experts believe that consuming healthy bacteria, called probiotics, improves the body's overall balance of good versus bad micro-organisms, boosting general health. But nutritionists warn that not all the probiotic-containing products found on store shelves provide the health benefits they claim... To be sure, some regular foods contain healthy bacteria, from common yogurt to naturally fermented pickles. But pasteurization has eliminated much of the flora found in modern foods. The recent boom in probiotic products reflects an effort to re-introduce bacteria believed to promote good health. Probiotics are generally considered safe to eat, but scientists say people with immune deficiencies should consult their doctor first.
Companies that sell products with added probiotics claim they offer a range of health benefits, from helping with digestion to boosting the immune system and preventing cavities. Some of the claims are based on reputable scientific study. But others are unproved, and advertising pitches are sometimes exaggerated. The quality of probiotic supplements also varies widely. As a result, consumers might have a difficult time choosing among a host of products. Of several hundred probiotic-product lines on the market in North America, "15 to 20 have clinical studies behind them," says Gregor Reid, a professor of microbiology at the University of Western Ontario's Lawson Research Institute.
(snip)
In choosing a probiotic, consumers should look for products that list a specific strain of bacteria on their label or on a Web site. Look for three names -- in Lactobacillus rhamnosus GG, for example, the final two letters identify the strain. The GG strain has been well tested scientifically and has shown health benefits. A product that simply uses the first two names may include a similar, but not identical, bacterium that doesn't have the same science behind it.. Say, for example, you want information on the active bacteria in Activia, a probiotic-enhanced yogurt from Dannon Co. The product label identifies the strain as Bifidus Regularis, but this is only a marketing name. The Activia Web site, under the tab "for health-care professionals," links you to summaries of scientific papers that use the scientific name, Bifidobacterium animalis DN-173 010, which has been found to hasten digestion. For additional information, you can do an Internet search of that name and many of the scientific studies on the strain pop up.
(snip)
Here are some claims probiotic manufacturers make for their products:
Faster Digestion: Dannon's Activia yogurt and Yoplait Yo-Plus yogurt, made by General Mills Inc., contain bacteria that have been shown in scientific studies to reduce "transit time" of waste through the intestines. Slow digestion isn't necessarily bad but can cause discomfort, such as bloating or constipation.
Irritable Bowel Syndrome: This disorder, including cramping, abdominal pain, bloating, constipation and diarrhea, can be disabling. A scientific task force, which published its findings in the American Journal of Gastroenterology this month, concluded that certain probiotic bacteria -- primarily bifidobacteria -- have shown "some efficacy" in treating the condition.
Colic: When babies scream or cry with no apparent reason, it's called colic. A study of 83 infants, published last year in the journal Pediatrics found that five drops a day of a probiotic supplement from Sweden's BioGaia AB reduced median crying time from 197 minutes a day to 51 minutes. A control group of babies was given a liquid medication commonly used to treat colic but not widely viewed as effective; this group's crying fell to a median of 145 minutes a day.
Immune Health: Studies have long found that probiotics help regulate the immune system on a biochemical level. A small but growing number of studies are showing concrete health benefits in humans. Among them is an Israeli study that looked at Lactobacillus reuteri 55730 and Bifidobacterium lactis Bb-12. Published in 2005 in Pediatrics, the three-month study of 201 infants found that babies fed with either of the two probiotic formulas had fewer episodes of fever and diarrhea than babies fed a control formula. Of the two bacteria, L. reuteri was more effective in preventing illness, the study found.
(snip)
http://online.wsj.com/article/SB123180831081775767.html (subscription)