Probiotics in Pediatric Medicine (eBook)

TABLE OF CONTENTS / ORGANIZATION
I Introductory Chapters

1. Basics of GI Physiology and Mucosal Immunology (A Fasano)
This introductory chapter will provide an overview of the gastrointestinal physiology and mucosal immunity as it relates to the gut with its microflora and its role in the overall health of the child.

2. Basics of Gut Microflora (G Tannock)
This chapter will cover the significance of microflora and the traditional and molecular advances in identifying gut microflora.

3. Role of Microflora in Disease (M. Relman).
The focus of this chapter is to review the role of microflora in gastrointestinal disorders with a focus on inflammatory bowel disease and irritable bowel syndrome. A review of the role of microflora in non-gastrointestinal disease such as atopic disorders will be included.

4. Probiotics 101 (WA Walker).
This chapter will provide the history of probiotic use and the basics for probiotic concepts as it relates to children.

5. Mechanism of Action of Probiotics (B Polk).
This chapter will review the basic research pertaining to the mechanism of action of probiotics as evidence by cellular/molecular studies as well as animal studies.

6. Safety of Probiotics (D Mack).
The safety of the different types and forms of probiotics will be reviewed with a focus on children.


Michail, Probiotics—p. 4

II Infant Health and Probiotics

7. Neonatal and Infant Microflora (JI Gordon)
This chapter will identify the development of microflora in the newborn infant and the factors that affect the composition of microflora such as breast feeding versus formula feeding, age of infant and child, mode of child delivery etc…

8. Probiotics in Infant Dietetics (Agostoni).
This chapter will review the evidence, or lack thereof,to support the benefit of adding probiotics to infant formulas or infant foods.

9. Probiotics and Nectrotizing Enterocolits (Zvi Weizman).
The focus of this chapter will be the role of probiotics and prevention or treatment of necrotizing enterocolitis.


III Pediatric GI and Related Diseases - Is There a Role for Probiotics?

10. Irritable Bowel Disease (S Michail).
A review of the literature with regards to irritable bowel syndrome will be presented in this chapter. Pediatric data will be reviewed.

11. Infectious Diarrhea (G Fuchs)
The role of probiotics in treating and preventing infectious diarrhea in pediatric patients will be covered in this chapter.

12. Crohn’s Disease (A Bousvaros)
The role of probiotics in treatment and prevention of relapse of Crohn’s disease will be reviewed in this chapter. Pediatric data will be discussed as well.

13. Ulcerative Colitis (PM Fedorak)
The role of probiotics in treatment and prevention of relapse of ulcerative colitis will be reviewed in this chapter. Any pediatric data will be reviewed.

14. Pouchitis (P Gionchetti)
The role of probiotics in prevention and treatment of pouchits will be reviewed in this chapter. Pediatric data will be discussed as well.

15. Antibiotic-associated Diarrhea and Clostridium difficile Infection
(H Szajewska).
The role of probiotics and treatment and prevention of these disorders with review of the evidence and meta-analysis will be discussed in this chapter.

16. Probiotics in the Immune-compromised Host (T Poussa).
This chapter will review the published studies related to the use of probiotics in various disorders affecting the host immune response and immunocompromised states.
Michail, Probiotics—p. 5

17. H. Pylori Infection (PM

INTESTINAL MICROBES AS A SOURCE OF MATURATIONAL SIGNALS TO THE DEVELOPING INTESTINE – A WINDOW OF OPPORTUNITY FOR PROBIOTIC INTERVENTION (S. 46-47)

In addition to affecting gut microbiota composition, probiotics may have direct effects on infant gut. It is well established that the neonatal intestine and the intestinal immune system in particular are dependent on external stimuli to become fully developed. The establishment of indigenous intestinal microbiota coincides with this maturational process and accumulating experimental data demonstrate that, in addition to breast milk, intestinal microbes provide the developing gut with maturational stimuli. It is therefore plausible that these developmental processes may be susceptible to manipulation by probiotics administered in the postnatal period [4] .

Colonization of the sterile neonatal gastrointestinal tract begins with first contact of the extrauterine environment. It is well established that a number of environmental factors, including mode of delivery [36] , feeding practices (breast milk versus formula [37] ) and treatment with antibiotics and/or in a neonatal intensive care unit [38] may have an impact on early microbial colonization.

Moreover, there are data indicating that the differences in intestinal microbiota composition between infants delivered vaginally or by caesarian section are still detectable at one year of age [36] . Disruptions in early colonization have been suggested to play a role in the pathogenesis of NEC in preterm infants [39] and the health benefits of breastfeeding have been partially attributed to the bifidogenic properties of breast milk [40] . As alluded to above, early aberrations in gut colonization have been shown to be associated with subsequent development of atopic eczema [29, 30] .

Given the immunological basis of the pathogenesis of atopic disease, this may be interpreted to imply a significant link between early colonizers and healthy immune development. Consequently, a hypothesis according to which changes in early microbial exposure resulting from lifestyle in the developed world, such as increasing caesarian sections and antibiotic use in infancy, changing pattern of infectious diseases, decreased importance of fermenting as a means to preserve food etc., may underlie the increase of immune-mediated disorders including atopic and autoimmune diseases has been proposed [14] .

This “hygiene hypothesis” was originally devised based on epidemiological findings linking decreased occurrence of infectious diseases in early childhood with increased risk of allergic disease [41, 42] . However, this view has subsequently been revised to emphasize the role of gut microbiota in healthy immune maturation [14] . The immunological processes resulting in gut immune maturation and establishment of tolerance toward indigenous microbes are not fully understood but both innate immune recognition mechanisms and adaptive immune responses orchestrated by dendritic cells and Tlymphocytes are involved. Studies conducted using experimental animal models suggest that toll-like receptors (TLRs), an evolutionarily conserved family of molecules, which recognize microbe-associated molecular patterns, are involved in recognizing and responding to initial pioneer colonizing bacteria.

Initially, TLRs have been implicated in innate immune defense against pathogens, but it appears that they may also have developmental and homeostatic functions. Germ-free rats colonized solely with Bifidobacterium lactis , a predominant component of gut microbiota in breastfed infants, have been observed to exhibit a transient and self-limiting TLR2- mediated inflammatory gene expression response in intestinal epithelial cells without evidence of inflammatory tissue damage [43] .