Prebiotics

Prebiotics is a term coined by Professor Gibson and a Belgian colleague, Dr. Marcel Roberfroid, of Louvain University in Brussels, in 1995. The word is generally defined as consisting of nondigestible food fibers which stimulate the growth and activity of certain bacteria in the intestines. Therefore, in order to be effective, a prebiotic must escape digestion in the upper gastrointestinal tract so that it can be released in the lower tract and used by beneficial microorganisms in the colon, mainly bifidobacteria and lactobacilli. Unlike probiotic bacteria, prebiotic carbohydrates are not destroyed when cooked.

Prebiotics consist mainly of oligosaccharides, sugar molecules of three to six chains and soluble fiber. Oligosaccharides coat mucus membranes and are found in plants, saliva, and breast milk. In fact, there are more than 130 different combinations of oligosaccharides in human breast milk alone. This could be a significant reason why breast-fed babies are healthier since they are naturally provided with the ingredients necessary to fight off harmful organisms and which will increase the developing beneficial ones.

Prebiotic Action
PRObiotic bacteria are not normally found in the human intestine. They also do not colonize well when introduced and are eliminated quickly. Therefore, PREbiotic foods are vital to encourage probiotic organisms to survive and thrive in the human gut. Beneficial bacteria must constantly be introduced in the diet and fed proper food to encourage them to adhere to the intestinal wall rather than passing through the digestive tract. This is important since there is a decided difference between the bacterial populations of vegetarians and meat-eaters – which explains why vegetarians are ill less often than those who eat meat.

The reason for this is that probiotic bacteria, and the short-chain fatty acids (SCFAs) that are produced by them, restrict the growth and activity of less beneficial species. In addition, the vegetarian intestinal tract discourages putrefactive and disease-causing bacteria and yeast because plant-based foods move out of the intestine more quickerly than do animal products. This “crowding out” of undesirable organisms is known as competitive exclusion, an action which promotes better gut integrity and function, increases immune system function, and improves calcium absorption and cholesterol maintenance.

In fact, most of the energy required by the colon is provided directly by SCFAs. If the colon does not have enough of them to meets its energy needs, decreased integrity and function follow, resulting in various “starved bowel” disorders known collectively as IBS (irritable bowel syndrome) or IBD (irritable bowel disease). For those sufferers, the prebiotics most recommended are lactosucrose, oligofructose, inulin, bran, psyllium, and germinated barley foodstuff (GBF).

Health Benefits
There is mounting scientific evidence that the symbiotic relationship between prebiotics and probiotics significantly contribute to health. Together, they

Prebiotic Foods
Prebiotic carbohydrates are found naturally in such fruit and vegetables as bananas, berries, asparagus, garlic, wheat, oatmeal, barley (and other whole grains), flaxseed, tomatoes, Jerusalem artichoke, onions and chicory, greens (especially dandelion greens but also spinach, collard greens, chard, kale, mustard greens, and others), andlegumes (lentils, kidney beans, chickpeas, navy beans, white beans, black beans, )

The various oligosaccharides classified as prebiotics and added to processed foods and supplements include Fiber gums, Fructo-oligosaccharides (FOS), Inulins, Isomalto-oligosaccharides, Lactilol, Lactosucrose, Lactulose, Oligofructose, Pyrodextrins, Soy oligosaccharides, Transgalacto-oligosaccharides (TOS), and Xylo-oligosaccharides. Each is dealt with separately under Prebiotic Substances.

Commercial Uses
The international consumer is well aware of the health benefits of prebiotics, gut integrity, probiotic microflora, and their respective roles in health maintenance. In the Americas, however, the concept of prebiotics is relatively new to the marketplace, with consumers just becoming aware of their importance. Prebiotics are being made available in almost every product imaginable ;and, as they become increasingly popular, more and more uses for them are going to be adopted by the commercial industry.

So far, such uses include kefir, yogurt and other dairy drinks, sports products, functional waters, nutrition bars, weight loss products, soymilk, infant foods and formulas, green foods, probiotic supplements, mineral supplements, medical foods, as well as pet foods and animal feeds.