November 16/Preventive Medicine Week -- Probiotics have become such a trend in consumer food products that their scientific evidence and clinical benefits may often be overlooked. However, probiotics, or "good bacteria," deserve attention from pediatric clinicians, said presenters at a satellite symposium during the 2007 meeting of the American Academy of Pediatrics (AAP) in San Francisco. Renowned experts in pediatrics, nutrition and gastroenterology addressed how intestinal microflora influence a child's developing immune system, as well as how disruptions to this normal microbial balance impact infectious, inflammatory and allergic diseases in children.

The symposium, Probiotics in Pediatrics: Modulating Gut Immunity and Enhancing Long-Term Health, explored how greater understanding of the intestinal microflora and its role in the development of the infant immune system has led to increased interest from pediatricians.

W. Allan Walker, M.D., a Conrad Taff professor of Nutrition at Harvard Medical School in Boston, discussed the roles of intestinal microflora and the initial colonization of bacteria as they relate to immunity. According to the hygiene hypothesis, cleanliness and lack of exposure to various microorganisms can have a direct effect on our immune systems. Public health measures such as pasteurization and sterilization of foods, increased use of antibiotics, and the rising number of cesarean sections have led to a decreased exposure to microorganisms. In infants, this can cause an increased disease burden as the mucosal immune system fails to develop properly. The timing of appropriate colonization correlates with development of host defenses and prevention of diseases.

Inadequate colonization can be overcome by the use of probiotics as "surrogate" colonizers. Martin G. Martin, M.D., a professor of Pediatrics at David Geffen University of California Los Angeles School of Medicine in Los Angeles discussed how studying the role of the intestinal microflora in health and disease states is crucial due to a rise in allergic and autoimmune disorders in infants (or children). Martin discussed the evidence for introduction of safe bacteria to infant nutrition and highlighted how certain probiotics have potential benefits on the gut and immune functions that are at a critical stage in development in infancy.

Not all probiotics are the same, however. Erika Isolauri, M.D., a professor in the department of Pediatrics at University of Turku in Turku, Finland, narrowed the concept of probiotics to its role in pediatrics and discussed how this requires a focus on several specific strains of bacterial species. For example, recent research confirms that breast milk contains bifidobacteria and specific Bifidobacterium species that may promote healthy microbiota development. Bifidobacterium species have been specifically studied in the pediatric population and have shown positive benefits in GI tract infections and antibiotic-associated diarrhea. Numerous studies have addressed the safety and efficacy of probiotics, including a clinical study that examined the role of probiotics in reducing acute diarrhea and atopic eczema with Lactobacilli strains.

The challenge, moving forward, is to explore the mechanism of how the specific strain has its benefit in order to identify the most appropriate host.

This symposium was sponsored by the Albert Einstein College of Medicine and Montefiore Medical Center, and supported by an educational grant from Nestle Nutrition Institute.

From the November 19, 2007, Prepared Foods e-Flash