Role of Probiotics & Prebiotics

The nutritional benefits of both probiotics and prebiotics are essential to a healthy diet, playing an important role in the digestive process and regulating bacterial growth in the stomach. Nevertheless, many diets do not emphasize the importance of these "good" bacteria.

Identification

• Although their names are quite similar, there are some important differences between probiotics and prebiotics. The International Scientific Association for Probiotics and Prebiotics defines probiotics as "...live microorganisms which when administered in adequate amount confer a health benefit on the host." Prebiotics, on the other hand, are defined as "...non-digestible substances that when consumed provide a beneficial physiological effect on the host by selectively stimulating the favorable growth or activity of a limited number of indigenous bacteria." In other words, prebiotics stimulate the growth of helpful bacteria, although they themselves are not digested; unlike probiotics, which are a kind of bacteria that live in the digestive tract.

Benefits

• The health benefits of probiotics and prebiotics are numerous. Probiotics have been proven to help relieve symptoms of lactose intolerance, boost the immune system, and prevent diarrhea and colon cancer. Prebiotics have been shown to relieve constipation and diarrhea, and reduce the chances of osteoporosis and Type 2 diabetes. However, as noted in the American Journal of Clinical Nutrition's online article by Marcel Roberfroid, prebiotics are a recent discovery, making scientific data limited and tentative. Probiotics were discovered in the early 20th century, so research and scientific data are much more reliable regarding their uses and benefits.

Function

• Probiotics function by balancing the good and bad bacteria in the gut. As noted at healthyeatingclub.com, these bacteria are best introduced into the gut through active sources, such as yogurt. Supplements in pill form are sometimes unsuccessful. Prebiotics are able to recognize helpful bacteria in food that has been ingested and help them grow in the intestines.

Theories

• In 2008, scientific research demonstrated that the use of probiotics may not always be beneficial. The studies revealed that the use of probiotics in treatment of eczema, childhood allergies, and pancreatic disorders may even be harmful to patients. Prebiotics, however, are recommended, according to Anna Denny, a nutrition scientist at the British Nutrition Foundation. "Whereas probiotics provide new doses of bacteria, prebiotics nourish and feed the friendly bacteria already present," says Denny. The studies suggest that the fostering of native, beneficial bacteria is safer than the introduction of foreign bacteria into the gut, regardless of the fact that they are usually considered "good" bacteria. According to Professor Glenn Gibson, one of the UK's leading experts on probiotics and prebiotics, "Research on prebiotics is in its infancy, but is very encouraging. Not all probiotics are unhelpful. Some people can benefit. But if I was asked to choose, then I'd take prebiotic every time."

Sources

• Probiotics can be found in yogurt, buttermilk, kefir, aged cheeses, brine-cured pickles and miso (as well as many other fermented soy products). Prebiotics are primarily found in oats, chicory, bananas, onion and garlic.