Prebiotics

Revision as of 14:04, 28 February 2011 by Steven2 (Talk | contribs)

Prebiotics are non-digestible food ingredients that stimulate the growth and/or activity of bacteria in the digestive system in ways claimed to be beneficial to health.As a functional food component, prebiotics, like probiotics, are conceptually intermediate between foods and drugs, and typically receive, depending on the jurisdiction, an intermediate level of regulatory scrutiny, in particular of the Health claims on food labels health claims made concerning them.

Typically, prebiotics are carbohydrates (such as oligosaccharides), but the definition may include non-carbohydrates. The most prevalent forms of prebiotics are nutritionally classed as soluble fiber. To some extent, many forms of dietary fiber exhibit some level of prebiotic effect.

Function

The prebiotic definition does not emphasize a specific bacterial group. Generally, however, it is assumed that a prebiotic should increase the number and/or activity of bifidobacteria and lactic acid bacteria. The importance of the bifidobacteria and the lactic acid bacteria (AKA lactobacillus or LABs) is that these groups of bacteria have several beneficial effects on the host, especially in terms of improving digestion (including enhancing mineral absorption<ref>Coxam V; Current data with inulin-type fructans and calcium, targeting bone health in adults. J Nutr. 2007; 137(11 Suppl): P-2527S</ref>) and the effectiveness and intrinsic strength of the immune system.<ref>Stephanie Seifert and Bernhard Watzl; Inulin and Oligofructose: Review of Experimental Data on Immune Modulation. J Nutr. 2007; 137: 2563S</ref> A product that stimulates bifidobacteria is considered a bifidogenic factor. Some prebiotics may thus also act as a bifidogenic factor and vice versa, but the two concepts are not identical.<ref>Food-Info.net Wageningen University</ref>

Sources

Traditional dietary sources of prebiotics include soybeans, inulin sources (such as Jerusalem artichoke, jicama, and Chicory root), raw oats, unrefined wheat, unrefined barley and yacon. Some of the oligosaccharides that naturally occur in breast milk are believed to play an important role in the development of a healthy immune system in infants.

It is becoming more common to properly distinguish between prebiotic substances and the food that contains them. References to almonds, honey and other foods (most commonly in promotional materials from growers of those foods) as "a prebiotic" are not accurate. No plant or food is a prebiotic: Wheat, honey and many other foods contain prebiotics to a greater or lesser extent, ranging from fairly large portions (chicory root, Jerusalem artichoke) to only trace quantities (thousands of other plant-based foods). Referring to a food as "a prebiotic" is no more accurate than calling a food "a vitamin."

Top 10 Foods Containing Prebiotics

Food Prebiotic Fiber Content by Weight
Raw Chicory Root 64.6%
Raw Jerusalem Artichoke 31.5%
Raw Dandelion Greens 24.3%
Raw Garlic 17.5%
Raw Leek 11.7%
Raw Onion 8.6%
Cooked Onion 5%
Raw Asparagus 5%
Raw Wheat bran 5%
Whole Wheat flour, Cooked 4.8%
Raw Banana 1%

While there is no broad consensus on an ideal daily serving of prebiotics, recommendations typically range from 4-8g for general digestive health support, to 15g or more for those with active digestive disorders. Given an average 6g serving, below are the amounts of prebiotic foods required to achieve a daily serving of prebiotic fiber:

See also

References

External links

Last modified on 28 February 2011, at 14:04