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- Adlerberth, Ingegerd, 1959, et al.
(författare)
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Gut microbiota and development of atopic eczema in 3 European birth cohorts.
- 2007
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Ingår i: The Journal of allergy and clinical immunology. - : Elsevier BV. - 0091-6749 .- 1097-6825. ; 120:2, s. 343-50
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Stimulation of the immune system by gut microbes might prevent allergy development. OBJECTIVE: The present study examined the hypothesis that sensitization to food allergens and atopic eczema are influenced by the infantile intestinal colonization pattern. METHODS: Infants were recruited perinatally in Göteborg (n = 116), London (n = 108), and Rome (n = 100). Commensal bacteria were identified to the genus or species level in rectal (3 days) and quantitative stool cultures (7, 14, and 28 days and 2, 6, and 12 months of age). At 18 months of age, atopic eczema and total and food-specific IgE levels were assessed. These outcomes were modeled in relation to time to colonization with 11 bacterial groups and to ratios of strict anaerobic to facultative anaerobic bacteria and gram-positive to gram-negative bacteria at certain time points. Study center, mode of delivery, parity, and infant diet were included as covariates. RESULTS: Neither atopic eczema nor food-specific IgE by 18 months of age were associated with time of acquisition of any particular bacterial group. Cesarean section delayed colonization by Escherichia coli and Bacteroides and Bifidobacterium species, giving way to, for example, Clostridium species. Lack of older siblings was associated with earlier colonization by Clostridium species and lower strict anaerobic/facultative anaerobic ratio at 12 months. CONCLUSIONS: This study does not support the hypothesis that sensitization to foods or atopic eczema in European infants in early life is associated with lack of any particular culturable intestinal commensal bacteria. CLINICAL IMPLICATIONS: The nature of the microbial stimulus required for protection from allergy remains to be identified.
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| 2. |
- Wang, Mei, et al.
(författare)
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Reduced diversity in the early fecal microbiota of infants developing atopic eczema
- 2008
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Ingår i: Journal of Allergy and Clinical Immunology. - : Elsevier BV. - 1097-6825 .- 0091-6749. ; 121:1, s. 129-134
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Tidskriftsartikel (refereegranskat)abstract
- Background It might be that early intestinal colonization by bacteria in westernized infants fails to give rise to sufficient immune stimulation to support maturation of regulatory immune mechanisms. Objective The purpose of the present study was to characterize the very early infantile microbiota by using a culture-independent approach and to relate the colonization pattern to development of atopic eczema in the first 18 months of life. Methods Fecal samples were collected from 35 infants at 1 week of age. Twenty infants were healthy, and 15 infants were given diagnoses of atopic eczema at the age of 18 months. The fecal microbiota of the infants was compared by means of terminal restriction fragment length polymorphism (T-RFLP) and temporal temperature gradient gel electrophoresis (TTGE) analysis of amplified 16S rRNA genes. Results By means of T-RFLP analysis, the median number of peaks, Shannon-Wiener index, and Simpson index of diversity were significantly less for infants with atopic eczema than for infants remaining healthy in the whole group and for the Swedish infants when AluI was used for digestion. The same was found when TTGE patterns were compared. In addition, TTGE analysis showed significantly less bands and lower diversity indices for the British atopic infants compared with those of the control subjects. Conclusion There is a reduced diversity in the early fecal microbiota of infants with atopic eczema during the first 18 months of life.
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