Synbiotics for Good Gut Health
~ May 2006 No.205 ~
First it was probiotics. Then it was prebiotics. Now the two are being combined to produce synbiotics. The principal behind probiotics is that our gastrointestinal system is populated by a large number and variety of different bacteria. In very general terms, some of the bacteria contribute to our good health, but others are responsible for disease and infections. By consuming foods that contain probiotic bacteria, it is believed that the population of beneficial bacteria can be increased – perhaps only temporarily – and good metabolism, and heath will be achieved. However, finding bacteria that have probiotic properties has not been easy. In addition, since the probiotic bacteria that are consumed do not normally reside in the digestive system, they are soon washed out of the intestines if consumption of the probiotic product is stopped.
The concept of prebiotics was developed to overcome the technical problems associated with probiotics. Bacteria that live in our GI tract, survive and grow using the partially digested food that passes down from the small intestine to the large intestine. Detailed research has shown that some bacteria (bifido bacteria in particular) have very specific nutrient needs, and therefore by selecting specific foods or food ingredients, it is possible to increase the numbers of target bacteria. This has the advantage that no external bacteria are being given, but rather the numbers of resident bacteria are increased. During the period of consumption of the prebiotic, the numbers of specific bacteria have been shown to increase by up to 100 fold, but similar to the situation with probiotics, when the consumption of the prebiotic stops, the gut bacteria numbers quickly return to their original values.
Some products, called synbiotics, are now being sold that contain both probiotic bacteria and prebiotic sugars. Such products take advantage of both the addition of beneficial bacteria and the encouragement of the growth of resident beneficial bacteria. Fructo-oligosaccharides are the most common prebiotic sugar used in such products to-day but, in the future, other sugars will be used to target other bacteria besides bifidobacteria.
- Definition of Probiotic Bacteria
- Live microorganisms when administered in adequate amounts that confer a health benefit on the host. Note that foods that contain probiotic bacteria are also often referred to as probiotics (e.g. yogurt).
- Definition of Prebiotic
- A nondigestible food ingredient that beneficially affects the host by selectively stimulating the growth and / or activity of a limited number of bacteria in the colon.
- Examples of Prebiotic Sugars
- Fructo-oligosaccharides (inulin, FOS etc)
- Soy oligosaccharides
Handbook of Nutraceuticals and Functional Foods, CRC Press
Probiotics and prebiotics