Prebiotics definition

In recent studies, Glindemann et al. (1999, 2000) attempted to obtain definite answers to one of the basic problems of prebiotic phosphorus chemistry were there realistic enrichment mechanisms for the phosphorus derivatives required in prebiotic syntheses Only if the phosphorylating agents were present in concentrated form could successful reactions have taken place. 

Effects of prebiotics on mineral metabolism . Am J Clin Nut, 73, 459-464. Schrezenmeir J. anddeVreseM. (2001). Probiotics, prebiotics, and synbiotics - approaching a definition . Am J Clini Nutr, 73, 361-364. 

In other words, since we do not know, each of us is free to choose. Do as you wish so long as you show that it is possible, respecting the prebiotic conditions, to create life from inanimate matter. This is the challenge and the method is open-ended. The ambition of scientists working in the field would be simply to arrive at minimal life a system containing the minimal and sufficient molecular ingredients to be called alive (this notion will be discussed in detail later on in this book). Of course this also calls into question the definition of hfe, a difficult issue but not an unsolvable one, as we will also see in the next chapter. 

In the following I will present a model to tackle this question. We are at the level of speculations, but we will use some known facts. For example, let s start from the condensation of NCA-anhydrides, a reaction which, as we have seen in the previous chapter, is considered prebiotic. In this way, oligopeptides up to (say) a length of ten can be built, possibly under thermodynamic control, but starting from a definite set of conditions (amino-acid composition in the starting mixture, pH, salinity, etc.). We can assume, and this is actually quite reasonable, that in this way copious libraries of different decapeptides have been formed, each in a significant concentration. 

According to our definition a multicomponent reaction (MCR) comprises reactions with more than two starting materials participating in the reaction and, at the same time, the atoms of these educts contribute the majority of the novel skeleton of the product (Scheme 3.1) [1], For example, adenine may be formed by the addition of five molecules of isocyanic acid, a reaction of possible high prebiotic relevance [2]. 

Schrezenmeir, J. and de Vrese, M., Probiotics, prebiotics, and synbiotics approaching a definition, Am. J. Clin. Nutr., Suppl. 73, 361S, 2001. 

More recently, the latter prebiotic concept was revised. The authors come to the definition that prebiotics have to be resistant until they are fermented by the intestinal (i.e., not only colonic) flora. The balanced stimulation of growth and/or activity of the health-promoting bacteria in the gastrointestinal tract have to be demonstrated finally by performing studies in the target group to produce sound scientific data (36). 

The authors concluded that if the reduction of crying in infants fed formula with sn2-plamitate is simply due to the looser stools, one would not expect an effect using formulas with prebiotics that result in softer stools, and there would definitely not be a diurnal pattern of altered crying (random during the day and likely associated with time of passing stool). Therefore, this effect could not be attributed to softer stools alone, and the mechanism had not yet been revealed. 

TABLE 5.1 Current Definitions of Prebiotics and Dietary Fibers... 

Gibson GR, Scott KP, Rastall RA, et al. Dietary prebiotics Current status and new definition. Food Sci Technol Bull. 2010 7 1-19. COMMISSION DIRECTIVE 2008/100/EC of 28 Odober 2008 amending Council Directive 90/496/EEC on nutrition labelling for foodstuffs as regards recommended daily allowances, energy conversion factors and definitions. . 

Gibson GR, Scott KP, Rastall RA, et aL Dietary prebiotics current status and new definition. Food Sci Technol Bull Funct Foods. 2010 7... 

Human milk is a true prebiotic, and its neutral oligosaccharides are known as the main bifidus factor [404], which prevents digestive tract infections because it induces and improves the growth of good intestinal flora. The prebiotic concept was developed by Gibson and Roberfroid in 1995 [410]. According to their definition, a prebiotic effect is proven when bifidobacteria, lactobacilli, and other healthy bacteria are specifically stimulated and potentially harmful bacteria are depressed [411]. The concept of using prebiotics in infent formulas is related to three basic assumptions [412] ... 

A prebiotic is a selectively fermented ingredient that allows specific changes, both in the composition and/or activity in the gastrointestinal microflora that confers benefits upon host wellbeing and health is the updated definition of prebiotics (Gibson et al. 2004). Currently, only three dietary... 

---