Probiotics have become a hot topic among functional food advocates. Functional foods are those that go beyond merely supplying your body with nutrients. They confer positive benefits that promote health and fight disease -- especially disorders of the colon and gastrointestinal tract. Probiotics have also received a great deal of promotion by numerous food manufacturers who seek to profit from one of the latest trends in "food as medicine."
Friendly Microbes
Germs aren't all bad. In fact millions of bacteria live peacefully in your body, where they've developed a symbiotic relationship with your digestive tract, according to USProbiotics.org. These beneficial bacteria, called probiotics, help you maintain health by colonizing areas of the intestine that could otherwise be populated by harmful pathogens. Living in your gastrointestinal tract benefits these microbes by providing them with a source of food. Nondigestible carbohydrates called prebiotics pass into your large intestine intact, as your body doesn't have the ability to metabolize them. Fortunately, hungry probiotic bacteria readily devour these prebiotics.
Probiotic Strains
Probiotics are, in most cases, bacteria, though a species of yeast called Saccharomyces boulardii has also been classified as a probiotic.
The first probiotic strains of bacteria were identified by Nobel laureate Elie Metchnikoff in the early 1900s when he noted that the lactic acid bacteria that was used to create fermented milk products seemed to confer health benefits. Metchnikoff associated the longevity he observed in Bulgarian peasants with the quantities of yogurt they consumed, according to the 2007 edition of "Communicating Current Research and Educational Topics and Trends in Applied Microbiology." A strain of probiotic used as a starter culture in yogurt was even named for these prolific yogurt eaters: Lactobacillus delbreuckii bulgaricus. Lactobacillus is perhaps the most common probiotic bacteria, but other strains include Streptococcus thermophilus and Bifidobacterium.
Food Sources
Probiotics need to remain alive in a food product in order to confer health benefits. Currently, the main dietary sources of probiotics are fermented milk products. Lactic acid bacteria are commonly added to milk products in order to induce fermentation and create probiotic foods such as yogurt, kefir, cultured buttermilk, acidophilus milk and sour cream. Its important to look for "probiotic" on the label, as in some cases pasteurization has killed any probiotic bacteria that would otherwise be present.
In order to ensure your body's population of probiotic bacteria has enough nutrients to grow and thrive, eat plenty of prebiotic foods as well. Prebiotics include artichokes, onions, garlic, leeks and asparagus, according to the International Scientific Association for Probiotics and Prebiotics.
Supplements
In addition to food sources, live probiotic microorganisms are available in freeze dried encapsulated forms for purchase through natural foods distributors. According to the University of Mary Washington, over 20 different varieties of probiotic are available in capsules, and some versions are fortified with prebiotics. UMW recommends that you take two capsules, thrice daily with meals if you're treating a specific disorder, then reducing this to one capsule daily for maintenance.
References
- University of Guelph: Yogurt
- "Communicating Current Research and Educational Topics and Trends in Applied Microbiology"; Probiotics: 100 years (1907-2007) after Elie Metchnikoff's Observation; Kingsley C. Anukam et al; 2007
- University of Mary Washington: Probiotics
- International Scientific Association for Probiotics: Prebiotics: A Consumer Guide for Making Smart Choices and Prebiotics
- USProbiotics.org: Probiotic Basics
