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- Abrahamsson, Thomas, et al.
(författare)
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Low diversity of the gut microbiota in infants with atopic eczema
- 2012
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Ingår i: Journal of Allergy and Clinical Immunology. - New York, USA : Elsevier BV. - 0091-6749 .- 1097-6825. ; 129:2, s. 434-U244
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: It is debated whether a low total diversity of the gut microbiota in early childhood is more important than an altered prevalence of particular bacterial species for the increasing incidence of allergic disease. The advent of powerful, cultivation-free molecular methods makes it possible to characterize the total microbiome down to the genus level in large cohorts. OBJECTIVE: We sought to assess microbial diversity and characterize the dominant bacteria in stool during the first year of life in relation to atopic eczema development. METHODS: Microbial diversity and composition were analyzed with barcoded 16S rDNA 454-pyrosequencing in stool samples at 1 week, 1 month, and 12 months of age in 20 infants with IgE-associated eczema and 20 infants without any allergic manifestation until 2 years of age (ClinicalTrials.gov ID NCT01285830). RESULTS: Infants with IgE-associated eczema had a lower diversity of the total microbiota at 1 month (P= .004) and a lower diversity of the bacterial phylum Bacteroidetes and the genus Bacteroides at 1 month (P= .02 and P= .01) and the phylum Proteobacteria at 12 months of age (P= .02). The microbiota was less uniform at 1 month than at 12 months of age, with a high interindividual variability. At 12 months, when the microbiota had stabilized, Proteobacteria, comprising gram-negative organisms, were more abundant in infants without allergic manifestation (Empirical Analysis of Digital Gene Expression in R edgeR test: P= .008, q= 0.02). CONCLUSION: Low intestinal microbial diversity during the first month of life was associated with subsequent atopic eczema.
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| 2. |
- Abrahamsson, Thomas R, 1968-, et al.
(författare)
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Probiotics in prevention of IgE-associated eczema : a double-blind, randomized, placebo-controlled trial
- 2007
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Ingår i: Journal of Allergy and Clinical Immunology. - : Elsevier BV. - 0091-6749 .- 1097-6825. ; 119:5, s. 1174-1180
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: An altered microbial exposure may underlie the increase of allergic diseases in affluent societies. Probiotics may alleviate and even prevent eczema in infants. OBJECTIVE: To prevent eczema and sensitization in infants with a family history of allergic disease by oral supplementation with the probiotic Lactobacillus reuteri. METHODS: Double-blind, randomized, placebo-controlled trial, which comprised 232 families with allergic disease, of whom 188 completed the study. The mothers received L reuteri ATCC 55730 (1 x 10(8) colony forming units) daily from gestational week 36 until delivery. Their babies then continued with the same product from birth until 12 months of age and were followed up for another year. Primary outcome was allergic disease, with or without positive skin prick test or circulating IgE to food allergens. RESULTS: The cumulative incidence of eczema was similar, 36% in the treated versus 34% in the placebo group. The L reuteri group had less IgE-associated eczema during the second year, 8% versus 20% (P = .02), however. Skin prick test reactivity was also less common in the treated than in the placebo group, significantly so for infants with mothers with allergies, 14% versus 31% (P = .02). Wheeze and other potentially allergic diseases were not affected. CONCLUSION: Although a preventive effect of probiotics on infant eczema was not confirmed, the treated infants had less IgE-associated eczema at 2 years of age and therefore possibly run a reduced risk to develop later respiratory allergic disease. CLINICAL IMPLICATION: Probiotics may reduce the incidence of IgE-associated eczema in infancy.
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| 3. |
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| 4. |
- Björkstén, Bengt, et al.
(författare)
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Allergy development and the intestinal microflora during the first year of life
- 2001
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Ingår i: Journal of Allergy and Clinical Immunology. - 0091-6749 .- 1097-6825. ; 108:4, s. 516-520
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Tidskriftsartikel (refereegranskat)abstract
- Background: The intestinal microflora is a likely source for the induction of immune deviation in infancy. Objective: The purpose of this study was to prospectively relate the intestinal microflora to allergy development in 2 countries differing with respect to the prevalence of atopic diseases. Methods: Newborn infants were followed prospectively through the first 2 years of life in Estonia (n = 24) and Sweden (n = 20). By that age, 9 Estonian and 9 Swedish infants had developed atopic dermatitis and/or positive skin prick test results. Stool samples were obtained at 5 to 6 days and at 1, 3, 6, and 12 months, and 13 groups of aerobic and anaerobic microorganisms were cultivated through use of standard methods. Results: In comparison with healthy infants, babies who developed allergy were less often colonized with enterococci during the first month of life (72 % vs 96 %, P < .05) and with bifidobacteria during the first year of life (17 % to 39 % vs 42 % to 69 %, P < .05). Furthermore, allergic infants had higher counts of clostridia at 3 months (median value, 10.3 vs 7.2 log(10), P < .05). The prevalence of colonization with Staphylococcus aureus was also higher at 6 months (61 % vs 23 %, P < .05), whereas the counts of Bacteroides were lower at 12 months (9.9 vs 10.6 log(10), P < .05). Conclusion: Differences in the composition of the gut flora between infants who will and infants who will not develop allergy are demonstrable before the development of any clinical manifestations of atopy. Because the observations were made in 2 countries with different standards of living, we believe that our findings could indicate a role for the intestinal microflora in the development of and protection from allergy.
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| 5. |
- Björkstén, Bengt
(författare)
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The intrauterine and postnatal environments
- 1999
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Ingår i: Journal of Allergy and Clinical Immunology. - 0091-6749 .- 1097-6825. ; 104:6, s. 1119-1127
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Forskningsöversikt (refereegranskat)abstract
- Pregnancy is associated with a strong skewing toward T(H)2 cytokine pattern, which enables the survival of the fetus, including fetal allergen-specific immune responses, The postnatal maturation of the immune system which is characterized by the development of a balanced T(H)1/T(H)2 immunity is genetically determined and modified by the environment. The process seems to proceed at a slower rate in atopic than in nonatopic infants. There is a close immunologic interaction between the mother and her offspring through the breast milk. Individual variations in the composition of human milk may el,plain the controversy with regard to the possible allergy-preventive effects of breast-feeding. Recurrent respiratory infections have been suggested to enhance immune deviation. The microbial flora are a more likely source, however, because they are a major driving force in the maturation of the immune system. Changes in its composition, as a consequence of an altered lifestyle and diet, may play a role in the higher prevalence of allergy. So far, primary prevention of allergy has failed. Future studies should therefore focus on factors enhancing immune deviation (ie, "success" factors) rather than on "risk" factors. The intestinal microflora is one of these factors that deserves closer analysis.
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| 7. |
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| 8. |
- Casas, Rosaura, 1954-, et al.
(författare)
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Detection of IgA antibodies to cat, β-lactoglobulin, and ovalbumin allergens in human milk
- 2000
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Ingår i: Journal of Allergy and Clinical Immunology. - : Elsevier BV. - 0091-6749 .- 1097-6825. ; 105:6 part 1, s. 1236-1240
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Tidskriftsartikel (refereegranskat)abstract
- Background: The relationship between the development of allergy during infancy and breast-feeding remains controversial. This controversy may be due to individual variations in the composition of human milk. Antibodies to food antigens to which the mother is commonly exposed are present in the milk, but their relationship to allergy is still unknown. IgA antibodies to inhalant allergens have not been previously detected.Objective: Our purpose was to analyze secretory IgA antibody levels to cat, β-lactoglobulin, and ovalbumin allergens in colostrum and mature milk in relation to maternal allergy.Methods: Colostrum and samples of mature milk were obtained after 1 and 3 months of lactation from 53 nursing mothers (17 allergic and 36 nonallergic mothers) and were analyzed for total secretory IgA levels by ELISA and secretory IgA antibodies to cat, β-lactoglobulin, and ovalbumin by an enzyme-amplified ELISA. The specificity of the assays was confirmed by inhibition experiments.Results: Secretory IgA to cat, β-lactoglobulin, and ovalbumin allergens were detected in colostrum as well as mature milk. The levels of secretory IgA to ovalbumin were lower in colostrum from allergic mothers with P = .016, whereas the levels to β-lactoglobulin and cat were similar in the 2 groups. IgA antibodies to ovalbumin were detected in 94% of the colostrum samples from allergic and in all samples from nonallergic mothers, in 82% and 96%, respectively at 1 month, and 53% and 65% at 3 months. Fewer samples had detectable secretory IgA antibodies to β-lactoglobulin than to ovalbumin and cat, and only 33% and 10% of the samples from the allergic and nonallergic mothers, respectively, remained positive at 3 months. All the allergic mothers had detectable IgA to cat in colostrum, whereas 83% and 73% of the samples were positive at 1 and 3 months. The corresponding numbers were 93%, 81%, and 81% in the nonallergic mothers (not significant).Conclusion: Even a low level of exposure of the mucosa (eg, by inhalant allergens) can induce antibody secretion into the milk, both in allergic and nonallergic mothers. (J Allergy Clin Immunol 2000;105:1236-40.)
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| 9. |
- Dzidic, Majda, et al.
(författare)
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Aberrant IgA responses to the gut microbiota during infancy precede asthma and allergy development
- 2017
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Ingår i: Journal of Allergy and Clinical Immunology. - : MOSBY-ELSEVIER. - 0091-6749 .- 1097-6825. ; 139:3, s. 1017-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Although a reduced gut microbiota diversity and low mucosal total IgA levels in infancy have been associated with allergy development, IgA responses to the gut microbiota have not yet been studied. Objective: We sought to determine the proportions of IgA coating together with the characterization of the dominant bacteria, bound to IgA or not, in infant stool samples in relation to allergy development. Methods: A combination of flow cytometric cell sorting and deep sequencing of the 16S rDNA gene was used to characterize the bacterial recognition patterns by IgA in stool samples collected at 1 and 12 months of age from children staying healthy or having allergic symptoms up to 7 years of age. Results: The children with allergic manifestations, particularly asthma, during childhood had a lower proportion of IgA bound to fecal bacteria at 12months of age compared with healthy children. These alterations cannot be attributed to differences in IgA levels or bacterial load between the 2 groups. Moreover, the bacterial targets of early IgA responses (including coating of the Bacteroides genus), as well as IgA recognition patterns, differed between healthy children and children with allergic manifestations. Altered IgA recognition patterns in children with allergy were observed already at 1 month of age, when the IgA antibodies are predominantly maternally derived in breast-fed children. Conclusion: An aberrant IgAresponsiveness to the gutmicrobiota during infancy precedes asthma and allergy development, possibly indicating an impaired mucosal barrier function in allergic children.
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| 10. |
- Fagerås Böttcher, Malin, et al.
(författare)
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A TLR4 polymorphism is associated with asthma and reduced lipopolysaccharide-induced interleukin-12(p70) responses in Swedish children
- 2004
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Ingår i: Journal of Allergy and Clinical Immunology. - : Elsevier BV. - 0091-6749 .- 1097-6825. ; 114:3, s. 561-567
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Tidskriftsartikel (refereegranskat)abstract
- Background Bacterial signals play an important role in the maturation of the immune system. Polymorphisms in genes coding for receptors to bacterial components can alter the immune responsiveness of the host to microbial agents and may indicate the development of aberrant immune responses that are associated with immune-mediated diseases such as atopic diseases. Objective The study's objective was to investigate the relationship between TLR4 and CD14 gene polymorphisms, the LPS responsiveness of PBMCs, and the presence of asthma and allergic rhinoconjunctivitis in children. Methods The TLR4 (Asp299Gly) and CD14/−159 polymorphisms were determined in 115 Swedish children aged 8 and 14 years. LPS-induced IL-12(p70), IL-10, and IFN-γ responses of PBMCs from 69 of the children were analyzed by means of ELISA. The levels of soluble CD14 in serum samples were analyzed by means of ELISA, and the total IgE levels were analyzed by means of UniCAP Total IgE (Pharmacia Diagnostics, Uppsala, Sweden). Results Decreased LPS-induced IL-12(p70) and IL-10 responses were associated with the TLR4 (Asp299Gly) polymorphism and independently with asthma, especially atopic asthma. The TLR4 (Asp299Gly) polymorphism was associated with a 4-fold higher prevalence of asthma in school-aged children (adjusted odds ratio 4.5, 95% CI 1.1-17.4) but not to allergic rhinoconjunctivitis. Conclusion A TLR4 polymorphism modifies innate immune responses in children and may be an important determinant for the development of asthma. This may influence the outcome of intervention studies that use microbial stimuli as immune modulators.
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