by Paulette Avery, R.N., M.S.N., I.B.C.L.C.

Have you noticed all the TV ads for capsules, tablets, and especially for yogurt products, all claiming to improve your digestive health? So what is this all about? Read on to learn a little about probiotics, the active ingredient in many of these products.

Probiotics, as defined by the World Health Organization and the Food and Agriculture Organization of the United States, are "live microorganisms, which, when administered in adequate amounts, confer a health benefit on the host." The microorganisms referred to include yeasts, bacteria, and viruses that are visible only with the use of a microscope. In less official but easier to understand terms, probiotics are similar to the "good" or "friendly" bacteria found in the human gut. All of us have both healthful and unhealthful bacteria and other microorganisms on our skin and within our bodies all the time. When the helpful and harmful bacteria are in balance, we usually have immune and digestive systems that work as they should. If harmful bacteria multiply enough to unbalance the system, we become ill.'

When this happens, your doctor may order an antibiotic to kill off the harmful bacteria. Unfortunately, the drugs don't discriminate. They kill off both the harmful and healthful bacteria, which is why we often get unpleasant GI symptoms such as nausea and diarrhea when we take antibiotics. Taking probiotics in addition to the antibiotics may help return your system to a healthful balance. However, from the recommendation I just heard from pharmacologist Thomas Hale, PhD, wait until after you complete the course of antibiotics to take the probiotic product. If you take it while taking the antibiotics, the drug will destroy the probiotics too.

In addition to capsules, tablets, and powders, foods such as yogurt, miso, tempeh, fermented and unfermented milk, and some juices and soy products also contain probiotics. Lactobacillus and Bifidobacterium are the probiotics most commonly contained in these products.'

Interest in the use of probiotics is growing. In addition to their use after antibiotic therapy, some people take them because they believe they will help treat conditions such as vaginal infections, irritable bowel syndrome, and skin infections. Others use them to boost their immune system.'

Our mouths also contain a mix of microorganisms that can become unbalanced and result in conditions such as gum disease. Since research has established a strong link between gum disease and cardiovascular disease, a healthful balance in the mouth is important. Much less attention has been focused on this use for probiotics, but Dr. David G. Williams, in a recent issue of his newsletter Alternatives, states the opinion that balancing the bacteria in the mouth could improve the health of the millions of people who suffer from heart disease.

I've barely touched on this topic here, so if you want to know more, one place to begin is the National Institutes of Health Web site. Also be sure to discuss your use of probiotics and all other complementary/alternative medicines with your health care provider.

Paulette Avery is a registered nurse and a freelance writer specializing in health issues.