chapter  4
24 Pages

The Prebiotic Effect: Review of Experimental and Human Data

BySofia Kolida, Glenn R. Gibson

CONTENTS Prebiotic Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Established Prebiotics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Inulin and Oligofructose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 Lactulose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 Galacto-oligosaccharides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

Tentative Prebiotics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Isomaltooligosaccharides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 Xylooligosaccharides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 Soybean Oligosaccharides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

The concept of prebiotics was first introduced in 1995 by Gibson and Roberfroid as an alternative approach for gut microbiota modulation. One aspect was that it would overcome survivability issues of probiotics during storage and gastrointestinal passage and allow beneficial changes within indigenous populations. Current prebiotics act at the genus rather than species level. Prebiotics were defined “as non digestible dietary ingredients that beneficially affect the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon, thus improving host health [1].” Any dietary food ingredient that reaches the human cecum has the

potential of being prebiotic. However, based on the above definition, the criteria that have to be fulfilled for a dietary ingredient to be characterized as

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of

such are as follows:

• Nondigestibility: It must neither be hydrolyzed by brush border or pancreatic enzymes nor absorbed in the upper part of the gastrointestinal tract. The best approach to confirm nondigestibility of a potential prebiotic is through administration to ileostomy patients and measuring its recovery at the terminal ileum. However, in most cases it is impractical to test the plethora of emerging prebiotics in such a manner. Alternative approaches for obtaining indications on the nondigestibility of a test prebiotic may be: A detailed description of its chemical structure to predict susceptibility to human enzyme degradation, measurement of its stability in gastric juice, measurement of its resistance to pancreatic enzymes and possibly of its resistance to brush border enzymes, although these are not as satisfactory as the ileostomy model [2].