| 1. |
- Simonyté Sjödin, Kotryna, et al.
(författare)
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Temporal and long-term gut microbiota variation in allergic disease : a prospective study from infancy to school age
- 2019
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Ingår i: Allergy. European Journal of Allergy and Clinical Immunology. - : John Wiley & Sons. - 0105-4538 .- 1398-9995. ; 74:1, s. 176-185
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Tidskriftsartikel (refereegranskat)abstract
- Background: Compositional changes in the early‐life gut microbiota have been implicated in IgE‐associated allergic diseases, but there is lack of longitudinal studies. We examined gut microbiota development from infancy to school age in relation to onset of IgE‐associated allergic diseases. At 8 years of age, we also examined the relationship between gut microbiota and T‐cell regulation, estimated as responses to polyclonal T‐cell activation.Methods: Stool samples were collected from 93 children at 4, 6, 13 months, and 8 years of age. The gut microbiota was profiled using 16S rRNA gene sequencing. Peripheral blood was drawn from all children, and mononuclear cells were polyclonally activated. Levels of IL‐10 and FOXP3 mRNA copies were determined using real‐time quantitative reverse transcriptase‐PCR.Results: At 8 years of age, 21 children were diagnosed with IgE‐associated allergic disease and 90% displayed allergic comorbidity. Seventy‐two children were nonallergic and nonsensitized. Statistical tests with multiple testing corrections demonstrated temporal underrepresentation of Ruminococcus and consistent underrepresentation of Bacteroides, Prevotella, and Coprococcus in allergic compared to nonallergic children from infancy to school age. The gut microbiota of the allergic 8‐year‐olds was enriched in Bifidobacteriumand depleted of Lactobacillus, Enterococcus, and Lachnospira. In allergic 8‐year-olds, Faecalibacterium correlated with IL‐10 mRNA levels (rs = 0.49, Padj = 0.02) with the same trend for FOXP3 (rs = 0.39, Padj = 0.08).Conclusions: We identified both temporal and long‐term variation in the differential abundance of specific bacterial genera in children developing IgE‐associated allergic disease. Improved dietary interventions aiming at expanding immune‐modulatory taxa could be studied for prevention of allergic disease.
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| 2. |
- West, Christina E, et al.
(författare)
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Effects of feeding probiotics during weaning on infections and antibody responses to diphtheria, tetanus and Hib vaccines.
- 2008
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Ingår i: Pediatric Allergy and Immunology. - : Wiley. - 0905-6157 .- 1399-3038. ; 19:1, s. 53-60
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Microbial exposure is necessary for the development of normal immune function, which has driven the idea of using probiotics for treatment and prevention of immune-mediated diseases in infancy and childhood. Mounting evidence indicates that probiotics have immunomodulatory effects. However, the mechanisms are still poorly understood. Specific antibody response is a valuable proxy for immune system maturation status in infancy. We aimed at determining the impact of Lactobacillus F19 (LF19) during weaning on infections and IgG antibody responses to routine vaccines. In a double-blind, placebo-controlled randomized intervention trial, infants were fed cereals with (n = 89) or without LF19 (n = 90) from 4 to 13 months of age. Infants were immunized with DTaP (diphtheria and tetanus toxoid and acellular pertussis), polio and Hib-conjugate vaccines at (3), 5(1/2) and 12 months of age. We assessed the number of days with infections, antibiotic prescriptions and antibody concentrations to Hib capsular polysaccharide (HibPS), diphtheria toxin (D) and tetanus toxoid (T) before and after the second and third doses. Days with infectious symptoms did not differ between the groups. Days with antibiotic prescriptions were fewer in the LF19 group (p = 0.044). LF19 enhanced anti-D concentrations when adjusting for breastfeeding duration and colonization with LF19 (p = 0.024). There was an interaction of the intervention and colonization with LF19 on anti-T concentrations during the course of vaccination (p = 0.035). The anti-HibPS concentrations were higher after the first and second dose of Hib vaccine in infants breastfed <6 months compared with those breastfed > or =6 months (p < 0.05), with no effect by LF19. In conclusion, feeding LF19 did not prevent infections, but increased the capacity to raise immune responses to protein antigens, with more pronounced effects in infants breastfed <6 months.
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| 3. |
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| 4. |
- West, Christina E, et al.
(författare)
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Probiotic effects on T-cell maturation in infants during weaning.
- 2012
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Ingår i: Clinical and Experimental Allergy. - : John Wiley & Sons. - 0954-7894 .- 1365-2222. ; 42:4, s. 540-549
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Tidskriftsartikel (refereegranskat)abstract
- Background: We previously reported that feeding the probiotic Lactobacillus paracasei ssp. paracasei F19 (LF19) during weaning reduced the cumulative incidence of eczema.Objective: To investigate the impact of feeding LF19 on T-cell maturation.Methods: One hundred and seventy-nine healthy, term infants with no prior allergic manifestations were randomized to daily intake of cereals with (n = 89) or without (n = 90) the addition of LF19 108 colony forming units per serving from 4 to 13 months of age. Venous blood was drawn at 5.5 and 13 months of age. We used the cytokine response to polyclonal T-cell stimulation by anti-CD3 plus anti-CD28 monoclonal antibodies, and in vitro stimulation with the vaccine tetanus toxoid (TT) as measures of global adaptive immunity and capacity to raise a specific T-cell response, respectively. Expression levels of IL-2, IFN-γ, IL-4, IL-17A and IL-10 messenger RNAs (mRNAs) were used as proxies for general T-cell stimulation and naive Th0 cells, Th1-, Th2-, Th17- and T regulatory lineages.Results: There was no difference between the two groups at 5.5 months of age. At 13 months, the polyclonal IL-2 response was higher in the placebo group (P < 0.05), whereas the IFN-γ/IL-2 (P < 0.01) and IL-17A/IL-2 (P < 0.05) ratios after polyclonal stimulation were higher in the probiotic group, as was the TT-specific IL17-A response (P < 0.001). In both groups, the IFN-γ and IL-4 responses increased from 5.5 to 13 months upon both polyclonal and specific stimulation (P < 0.01), whereas the IL-10 response remained low (P > 0.05).Conclusion and Clinical Relevance: Our findings suggest modest effects by probiotics on T-cell maturation following 9 months of probiotic intake. Future studies should address if specific probiotics may drive immune development with possible preventive effects on the development of allergic disease.
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| 5. |
- West, Christina E, et al.
(författare)
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Probiotics during weaning reduce the incidence of eczema.
- 2009
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Ingår i: Pediatric allergy and immunology : official publication of the European Society of Pediatric Allergy and Immunology. - : Wiley. - 1399-3038. ; 20, s. 430-7
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Tidskriftsartikel (refereegranskat)abstract
- A reduced microbial load early in life has been suggested to be linked to the increasing prevalence of allergic diseases in the industrialized world. Some studies have indicated that probiotics may be effective in the prevention of eczema. In vitro studies indicate that probiotics have immunomodulatory effects. In the present study, we evaluated the effects of feeding Lactobacillus F19 during weaning on the incidence of eczema and Th1/Th2 balance. In a double-blind, placebo-controlled randomized intervention trial, infants were fed cereals with (n = 89) or without Lactobacillus F19 (n = 90) from 4 to 13 months of age. We assessed the cumulative incidence of eczema at 13 months of age. The ratio of interferon-gamma (IFN-gamma) to interleukin 4 (IL4) mRNA expression levels in polyclonally stimulated peripheral blood T cells was used as a proxy for immune balance. Total and specific IgE serum levels were also assessed. The cumulative incidence of eczema at 13 months was 11% (4-17%, 95% CI) and 22% (13-31%, 95% CI) in the probiotic and placebo groups, respectively (p < 0.05). The number needed to treat was 9 (6.5-11.5, 95% CI). At 13 months of age, the IFN-gamma/IL4 mRNA ratio was higher in the probiotic compared with the placebo group (p < 0.05). In contrast, there were no differences between groups in serum concentrations of IgE. In summary, feeding Lactobacillus F19 during weaning could be an effective tool in the prevention of early manifestation of allergy, e.g., eczema. The higher Th1/Th2 ratio in the probiotic compared with the placebo group suggests enhancing effects of Lactobacillus F19 on the T cell-mediated immune response.
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| 6. |
- West, Christina E., et al.
(författare)
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Probiotics in primary prevention of allergic disease - follow-up at 8-9 years of age
- 2013
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Ingår i: Allergy. European Journal of Allergy and Clinical Immunology. - : Wiley. - 0105-4538 .- 1398-9995. ; 68:8, s. 1015-1020
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Tidskriftsartikel (refereegranskat)abstract
- Background: Long-term effects of probiotics in primary prevention of allergic disease need further evaluation. We previously reported a reduced cumulative incidence of infant eczema by feeding Lactobacillus paracasei ssp paracasei F19 (LF19) during weaning. Therefore, we assessed effects of LF19 on the prevalence of allergic disease at school age. Methods: In a double-blind placebo-controlled trial infants were randomized to daily intake of cereals with (n=89) or without LF19 10(8) CFU (n=90) from 4-13months of age. At age 8-9, we evaluated the prevalence of allergic disease (eczema, allergic rhinitis, asthma, and food allergy) by clinical examination and validated questionnaires. IgE sensitization was assessed by skin prick test (inhalant allergens) and specific IgE levels (food allergens). Lung function was evaluated by a spirometry reversibility test. Fractional exhaled nitric oxide (FENO) was measured. Results: Of 171 children that completed the intervention, 121 were assessed at age 8-9. In the probiotic group, 15/59 (25%) were diagnosed with any allergic disease vs 22/62 (35%) in the placebo group [OR (95% CI) 0.62 (0.28-1.36)]. Corresponding numbers for IgE-associated allergic disease were 9/53 (17%) vs 12/59 (20%) [0.80 (0.31-2.09)]. Median (25th-75th percentile) FENO was 9 (8-12) in the probiotic vs 8 (7-12) ppb in the placebo group (P>0.05). There was no effect of LF19 on lung function measures (P>0.05). Conclusions: There was no long-term effect of LF19 on any diagnosed allergic disease, airway inflammation or IgE sensitization. This suggests delayed eczema onset but to fully examine long-term benefits a larger study population had been needed.
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| 7. |
- West, Christina, 1969-
(författare)
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Feeding Lactobacillus paracasei ssp. paracasei strain F19 to infants during weaning : effects on adaptive immunity and gut microbial function
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: Gut microbial composition has been associated with immune-mediated diseases. Breastfeeding yields a microbiota rich in bifidobacteria and promotes colonization by lactobacilli. Bifidobacteria and lactobacilli are considered health-promoting and are used as probiotics, i.e. live microbial food supplements which when ingested in adequate amounts confer a beneficial effect on the host. During weaning the developing gut immune system is exposed to an increasing variety of antigens from both foods and gut microbiota.Aims: We aimed to determine if daily feeding of 1x108 colony-forming units (CFU) of the probiotic Lactobacillus paracasei ssp. paracasei strain F19 (LF19) to healthy term infants from 4 to 13 months of age could maintain some of the beneficial effects conferred by breastfeeding on gut microbial composition, with possible effects on gut microbial function, T cell function, Th1/Th2 immune balance and eczema incidence.Study design: Infants were randomized to daily intake of cereals with (n=89) or without LF19 (n=90) from 4-13 months of age. Clinical outcome measures were monitored by diaries and a questionnaire. Stool and blood samples were obtained at 4, 6½, 9, 13 and 5½, 6½, 12 and 13 months of age, respectively. Stool samples were analyzed for lactobacilli counts by conventional culture methods and the presence of LF19 was verified by randomly amplified polymerase chain reaction (RAPD-PCR). Fecal short-chain fatty acid (SCFA) pattern, a proxy for gut microbial function, was determined by gas-liquid chromatography. After polyclonal or specific activation of T cells, the cytokine mRNA expression levels [interleukin 2 (IL2), IFN-, IL4 and IL10] were determined on isolated mRNA by quantitative real time reverse transcriptase-PCR. Serum concentrations of total and specific IgE antibodies, Haemophilus influenzae type b, diphtheria and tetanus toxoid specific IgG antibodies were analyzed by enzyme immunoassay.Results: Feeding LF19 maintained high fecal lactobacilli counts during weaning. Persistent colonization with LF19 induced differences in the fecal SCFA pattern. The cumulative incidence of eczema was lower in the probiotic group, in conjunction with a higher IFN-γ/IL4 mRNA ratio in polyclonally activated T cells. Even though there was an effect by LF19 on Th1/Th2 immune balance, there was no effect on IgE sensitization. Infants in both groups increased their capacity to express both Th1 and Th2 cytokines during the second half of infancy but the expression was still lower than that of adults. Infants in the probiotic group had lower IL2 levels after polyclonal T cell activation at 13 months of age compared with infants in the placebo group. Infants fed LF19 did not have fewer infections, but had fewer days with antibiotic prescription compared with infants fed placebo. In addition, compared to placebo, persistent colonization by LF19 enhanced specific vaccine responses to protein antigens during the course of vaccination.Conclusions: We conclude that feeding LF19 was safe, based on no observed adverse effects in our study. Infants in both groups demonstrated maturation of adaptive immune responses during weaning. Adding probiotics in complementary foods during weaning reduced the risk of eczema by 50%, with a concomitant shift towards an enhanced Th1/Th2 ratio. The reduction of eczema might be explained by probiotic effects on both T cell-mediated immune responses and reinforced gut microbial function.
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