Prebiotics are non-digestible food ingredients that beneficially affect the gut by selectively stimulating the growth and/or activity of one or more beneficial bacteria in the colon, thus improving health. Fructooligosaccharides (FOS) are one of the many classes of probiotics and they're found in legumes, vegetables, and cereals as well as yogurt. These non-absorbed fibres inhibit potentially pathogenic organisms as well as increase the absorption of minerals such as calcium, magnesium, iron, and zinc.

Probiotics are defined as live micro-organisms that, when taken in adequate amounts, can be of benefit to our health. The evidence for the role of prebiotics and probiotics in promoting health and fighting disease is increasing on a monthly basis and is now supported by many double-blind, placebo-controlled human trials. What used to be folklore has become scientific fact. This mounting body of very recent news simply confirms ancient wisdom.

Like all of the Superfoods, yogurt works synergistically to promote health and fight disease: it provides a range of health benefits that include live active cultures, protein, calcium, and B vitamins, which work together in such a way that the sum is greater than the parts. Yogurt's primary benefit-as a probiotic-is something that at first glance runs counter to the trend in modern medicine. With the success of antibiotics beginning shortly after World War II, doctors and the public have come to view micro-organisms as evil disease-promoters, which must be relentlessly eradicated. In fact, however, the key to health is balance: the goal is not to eradicate all micro-organisms, but rather to promote the health of the beneficial ones. Yogurt plays a primary role in this promotion by encouraging the growth of "good" bacteria and limiting the proliferation of 'bad" ones.

Yogurt has multiple immune stimulating properties both inside and outside the gastrointestinal (Gl) tract. An interesting study has shown that if you eat yogurt with live active cultures, you decrease the amount of a common pathogenic bacterium - Staphylococcus aureus - in the nasal passages. This is a clear sign that the yogurt is stimulating the immune system.

Our gastrointestinal tracts are home to over five hundred species of bacteria-some helpful and some harmful to our health. We rely on these beneficial microbial partners for a number of important functions, including carbohydrate metabolism, amino acid synthesis, vitamin K synthesis, and the processing of various nutrients. Yogurt is a source of beneficial bacteria, and the positive results that are ascribed to introducing this bacteria to our system are not relegated to the digestive tract.

While a host of beneficial health effects are linked to yogurt, those that have attracted the most attention include its anti-cancer properties, its ability to lower cholesterol, and its ability to inhibit unfriendly bacteria.

One of the great benefits of the probiotics in yogurt is its ability to strengthen the immune system and thereby help the body prevent infection. In an era of antibiotic-resistant pathogens and seemingly new infectious threats like SARS and West Nile virus, the value of boosting one's immune system becomes immeasurable.

There are three basic types of yogurt, depending on the milk used to make it: regular yogurt, low-fat yogurt, and non-fat yogurt. Yogurt made from whole milk has at least 3.25 percent milk fat. Low-fat yogurt is made from low-fat milk or part-skim milk and has between 0.5 and 2 percent milk fat. Non-fat yogurt is made from skim milk and contains less than 0.5 percent milk fat.

Ultimately, it's yogurt's activity in the gastrointestinal tract that argues most conclusively for its inclusion as a Superfood. The bottom line is that a healthy digestive system is critical to good health. Our ability to absorb nutrients from our food depends on our GI health. Even if we eat the most nutrient-dense foods in the world, if our digestive ability is impaired, we won't be able to benefit from those foods. As we age, our digestive ability is often diminished. All the more reason to rely on yogurt as a food that will promote and help preserve intestinal health.

The list of the health-promoting abilities of probiotics is quite long. Some benefits have been proven conclusively while others require more study. Here is a summary of the conditions where yogurt has efficacy:

Probiotics absorb mutagens that cause cancer, particularly colon cancer, though there's also evidence that they're effective on breast cancer. They stimulate the immune system, partly by promoting immunoglobulin production, and help lower the risk for cancer by decreasing inflammation and inhibiting the growth of cancer-causing intestinal microflora.

Probiotics are helpful in alleviating atopic eczema and milk allergies. In relation to eczema, it's important to remember that probiotics work to promote healthy skin as well as a healthy digestive tract. Indeed, probiotics affect all surfaces of the body that have interaction with the external world, including nasal passages, the gastrointestinal tract, the skin and so forth. There's some evidence that babies who are exposed to probiotics (after the age of three months) will have a better chance of avoiding some allergies later in life.

Some people cannot tolerate milk because they lack the enzyme to break down milk sugar (lactose). In fact, only about a quarter of the world's adults can digest milk. This condition eliminates an important source calcium from the diet. Probiotics in yogurt digest the lactose for you, thus helping to relieve this condition. Yogurt is also a calcium- and vitamin-rich food that's easily digestible by those who suffer from lactose intolerance and is therefore an excellent addition to their diet.

Probiotics help regulate the body's inflammatory response, which relieves the symptoms of Inflammatory Bowel Disease (IBD). The probiotics in yogurt have been accepted as a form of therapy that can actually help maintain remission in people suffering from IBD. A 2003 review of human studies on probiotics concluded that 'the use of probiotics in IBD clearly will not provide a magical cure, but it does offer hope as an adjunct form of therapy, specifically in maintaining a state of remission."

Irritable Bowel Syndrome (IBS): Probiotics alter both the populations and the activities of the microflora in our gastrointestinal systems, possibly relieving the symptoms of IBS, though probiotics may prove to be more effective in prevention than in effecting a cure.

For hypertension, probiotics stimulate the production of drug like substances that act in the body like pharmacological blood-pressure-lowering medicines.

Over thirty years ago, scientists were intrigued to find that the Masai tribesmen of Africa had low serum levels of cholesterol as well as low levels of coronary heart disease, despite a diet that was extremely high in meat. The distinguishing characteristic of their diets, aside from high meat consumption, was an extremely high intake of fermented milk (or yogurt)-up to 5 liters daily. Research has now confirmed that yogurt is beneficial to those trying to reduce cholesterol. The probiotics in yogurt reduce the bile acids, which in turn decrease the absorption of cholesterol from the gastrointestinal tract. This effect seems to be seen most reliably in people who already have elevated cholesterol.

Yogurt even helps with ulcers. Probiotics help to eliminate the pathogen Helicobacter pylori, a bacterium that is one of the main causes of ulcers and may also be a cause of gastric cancer.

Yogurt has potential benefit in relieving what, in many countries around the world, is a serious threat to the health of millions; Diarrhea. It fights diarrhea by stimulating the immune system, crowding out negative microflora in the intestines and stimulating the growth of beneficial bacteria. Probiotics in yogurt are also helpful in treating diarrhea associated with antibiotic use, and some doctors are amazed that yogurt is not routinely recommended to all patients who are being treated with antibiotics.

Most people are surprised to learn that in the United States, nine out of ten women and seven out of ten men don't meet their daily requirement for calcium. What's even more troubling is that nearly 90 percent of teenage girls and 70 percent of teenage boys don't meet their daily calcium requirement. For many, soda has replaced the old "milk at every meal" custom. This portends disastrous future health consequences for large numbers of people. A single 1-cup serving of nonfat plain yogurt supplies 414 milligrams of calcium-an amazing 40 percent of your daily calcium needs and at a cost of only 100 calories. This compares favorably with nonfat milk, which has only 300 milligrams of calcium. The rich amount of potassium in yogurt combined with the calcium also plays a role in normalizing your blood pressure.

Yogurt is also a better source of B vitamins (including foliate), phosphorus, and potassium than milk. Of course, the calcium in yogurt is of great benefit to pre and postmenopausal women and to men and women in their struggle against osteoporosis. A rich source of calcium to begin with, the milk sugar in yogurt actually aids in calcium absorption. Moreover, dairy foods are a source of IGF-l, a growth factor that promotes bone formation, which benefits women over and above the bone-preserving contribution of calcium.

Yogurt is a great source of readily digestible protein. In fact, yogurt supplies double the protein of milk because it's usually thickened with non-fat milk solids, increasing its protein content. Some people, particularly the elderly, just don't consume enough protein or calcium. Studies have shown there's a positive association between protein intake and bone-mineral density of older women and men when they're supplemented with calcium. The lesson: optimum bone health and prevention of osteoporosis depend not just on calcium supplementation, but on sufficient protein intake as well. Yogurt, with its easily digestible protein and calcium, is the answer.