Probiotic Foods: Hype or Health?
Interestingly, your child's GI tract is as unique to him as his fingerprints are. Each child (and adult) has trillions of different microbes living in him, and no two kids have the same mix of bacteria. Two of the most common categories of beneficial bacteria that naturally occur in our body are called Lactobacillus and Bifidobacterium, and it is generally these healthy bugs that food manufacturers use in their products. The marketplace is rife with specific strains of each of these bacterial groups (such as Lactobacillus rhamnosus GG, Lactobacillus reuteri, and Bifidobacterium lactis). "Like antibiotics, probiotics are confusing to people because each one is different," says Dr. Merenstein. The antibiotic that will treat your child's ear infection won't necessarily treat her pneumonia. The same holds true for probiotics -- one strain does not prevent or treat all ailments.
And it's not just the strain that's important, but the dose. Some food product labels list strain names along with the amount of live bacteria, usually cited on labels exponentially as 109 (1 billion) or 1010 (10 billion) CFUs (colony forming units). However, many products don't provide this information, so you may need to contact the company or visit its Website to get the info.
As of now, there just aren't a lot of good studies showing that food products actually deliver their proposed benefits. Some experts believe that the best type of research involves a specific product rather than a particular probiotic strain. These kinds of studies are the only way to determine how many probiotic bacteria remain alive and kicking in the food after travel and shelf time. "Without them, we really don't know how well -- or how many -- live bacteria survive in products by the time they're eaten," says Dr. Merenstein. (Supplements, on the other hand, are usually freeze-dried and packaged so that they retain their bacteria.) Baby formulas containing probiotics also need to be studied more before they can be recommended, say experts.
Whatever the benefit, it's important to note that probiotics' infection-fighting effects are only temporary. This is because the probiotics don't build up in your child's gastrointestinal system. "Once you stop taking any probiotic, whether it's in food or in medicinal form, it disappears from the GI tract and your microflora levels return to what they were," says Frank R. Greer, M.D., professor of pediatrics at the University of Wisconsin, Madison, and a coauthor of the American Academy of Pediatrics' (AAP) report on probiotics, due out this fall.