ABSTRACT
Health and Well-Being . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 The Concept of Colonic Nutrients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Prebiotic: A Specific Colonic Nutrient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Prebiotic and Probiotic: Comparison of the Mechanism of Action . . . . . . . 9 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
A complex community of microorganisms inhabits the mammalian gastrointestinal tract from mouth to anus, but the colon is, by far, the main site of this microbial colonization [1]. Over the last 20-25 years, our knowledge on the complexity of this microbiota has increased considerably. Paramount to such aprogress is the development andvalidation of a diversity of new molecular-based microbiological methodologies that have provided unequivocal evidence of composition [2-4]:
• The identification of newdominant phyla/groups/species ofmicroorganisms (accounting for up to 65-70% of the whole microbiota) previously not accessible to the culture-based methods. As shown in Figure 1.1 and based on taxa (phyla and groups) analysis, the dominant human fecal flora is composed of 3 phyla, that is, Firmicutes, Bacteroidetes, and Actinobacteria that can represent
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of
up to 75% of the whole microbiota, and subdominant groups are enterobacteriacae, streptococci, and lactobacilli [5].
