Korean J Asthma Allergy Clin Immunol.
2007 Dec;27(4):220-225.
Intestinal Microbiota and the Development of Allergy in Infants
Abstract
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We analyzed fecal microbiota in Japanese infants with or without allergy at 6 months using a culture technique. Determination of allergy was based on clinical symptoms, signs, and skin prick test. There were no differences in frequencies or counts of 13 genera and yeast-like organisms at 6 months of age between allergic and non-allergic infants. Bifidobacterium was dominant in all infants irrespective of the presence or absence of allergy. We next investigated the composition of fecal Bifidobacterium species in allergic and non-allergic infants using Bifidobacterium species-specific or group- specific primers based on 16S rDNA sequences at 1, 3 and 6 months of age. At 1 month of age, allergic infants had a higher prevalence of B. catenulatum than on-allergic infants (60.0% vs. 6.3%, P<0.01). At 6 months of age, allergic infants had a higher prevalence of B. bifidum than non-allergic infants (70.0% vs. 12.5%, P<0.01). These differences were not related to feeding methods. Finally, we studied the activity of B. bifidum in comparison with B. adolescentis to induce TNF-alpha and IL-10 from cord blood mononuclear cells. The results suggest B. bifidum has lower activity to induce both cytokines compared to B. adolescentis, suggesting that colonization of lower cytokine producing Bifidobacterium species or strains may be a risk factor for the development of allergy in infancy.