| 1. |
- Forsberg, Anna, et al.
(författare)
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Pre- and probiotics for allergy prevention: time to revisit recommendations?
- 2016
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Ingår i: Clinical and Experimental Allergy. - : WILEY-BLACKWELL. - 0954-7894 .- 1365-2222. ; 46:12, s. 1506-1521
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Forskningsöversikt (refereegranskat)abstract
- Reduced intensity and diversity of microbial exposure is considered a major factor driving abnormal postnatal immune maturation and increasing allergy prevalence, particularly in more affluent regions. Quantitatively, the largest important source of early immunemicrobial interaction, the gut microbiota, is of particular interest in this context, with variations in composition and diversity in the first months of life associated with subsequent allergy development. Attempting to restore the health consequences of the ` dysbiotic drift in modern society, interventions modulating gut microbiota for allergy prevention have been evaluated in several randomized placebo-controlled trials. In this review, we provide an overview of these trials and discuss recommendations from international expert bodies regarding prebiotic, probiotic and synbiotic interventions. Recent guidelines from the World Allergy Organization recommend the use of probiotics for the primary prevention of eczema in pregnant and breastfeeding mothers of infants at high risk for developing allergy and in high-risk infants. It is however stressed that these recommendations are conditional, based on very low-quality evidence and great heterogeneity between studies, which also impedes specific and practical advice to consumers on the most effective regimens. We discuss how the choice of probiotic strains, timing and duration of administration can critically influence the outcome due to different effects on immune modulation and gut microbiota composition. Furthermore, we propose strategies to potentially improve allergy-preventive effects and enable future evidence-based implementation.
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| 2. |
- West, Christina E., et al.
(författare)
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Bugging allergy; role of pre-, pro- and synbiotics in allergy prevention
- 2017
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Ingår i: Allergology International. - : JAPANESE SOCIETY ALLERGOLOGY. - 1323-8930 .- 1440-1592. ; 66:4, s. 529-538
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Forskningsöversikt (refereegranskat)abstract
- Large-scale biodiversity loss and complex changes in social behaviors are altering human microbial ecology. This is increasingly implicated in the global rise in inflammatory diseases, most notably the "allergy epidemic" in very early life. Colonization of human ecological niches, particularly the gastrointestinal tract, is critical for normal local and systemic immune development and regulation. Disturbances in composition, diversity and timing of microbial colonization have been associated with increased allergy risk, indicating the importance of strategies to restore a dysbiotic gut microbiota in the primary prevention of allergic diseases, including the administration of probiotics, prebiotics and synbiotics. Here, we summarize and discuss findings of randomized clinical trials that have examined the effects of these microbiome-related strategies on short and long-term allergy preventative effects - including new guidelines from the World Allergy Organization which now recommend probiotics and prebiotics for allergy prevention under certain conditions. The relatively low quality evidence, limited comparative studies and large heterogeneity between studies, have collectively hampered recommendations on specific probiotic strains, specific timing and specific conditions for the most effective preventive management. At the same time the risk of using available products is low. While further research is needed before specific practice guidelines on supplement probiotics and prebiotics, it is equally important that the underlying dietary and lifestyle factors of dysbiosis are addressed at both the individual and societal levels.
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| 3. |
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| 4. |
- West, Christina E., et al.
(författare)
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Probiotics for treatment and primary prevention of allergic diseases and asthma : looking back and moving forward
- 2016
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Ingår i: Expert Review of Clinical Immunology. - : Taylor & Francis. - 1744-666X .- 1744-8409. ; 12:6, s. 625-639
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Forskningsöversikt (refereegranskat)abstract
- Microbial ecosystems cover the surface of the human body and it is becoming increasingly clear that our modern environment has profound effects on microbial composition and diversity. A dysbiotic gut microbiota has been associated with allergic diseases and asthma in cross-sectional and observational studies. In an attempt to restore this dysbiosis, probiotics have been evaluated in randomized controlled trials. Here, we review treatment and primary prevention studies, recent meta-analyses, and discuss the current understanding of the role of probiotics in this context. Many meta-analyses have shown a moderate benefit of probiotics for eczema prevention, whereas there is less evidence of a benefit for other allergic manifestations. Because of very low quality evidence and heterogeneity between studies, specific advice on the most effective regimens cannot yet be given -not even for eczema prevention. To be able to adopt results into specific recommendations, international expert organizations stress the need for well-designed studies.
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| 5. |
- West, Christina E, et al.
(författare)
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The gut microbiota and inflammatory noncommunicable diseases: Associations and potentials for gut microbiota therapies
- 2015
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Ingår i: Journal of Allergy and Clinical Immunology. - : Elsevier. - 0091-6749 .- 1097-6825. ; 135:1
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Forskningsöversikt (refereegranskat)abstract
- Rapid environmental transition and modern lifestyles are likely driving changes in the biodiversity of the human gut microbiota. With clear effects on physiologic, immunologic, and metabolic processes in human health, aberrations in the gut microbiome and intestinal homeostasis have the capacity for multisystem effects. Changes in microbial composition are implicated in the increasing propensity for a broad range of inflammatory diseases, such as allergic disease, asthma, inflammatory bowel disease (IBD), obesity, and associated noncommunicable diseases (NCDs). There are also suggestive implications for neurodevelopment and mental health. These diverse multisystem influences have sparked interest in strategies that might favorably modulate the gut microbiota to reduce the risk of many NCDs. For example, specific prebiotics promote favorable intestinal colonization, and their fermented products have anti-inflammatory properties. Specific probiotics also have immunomodulatory and metabolic effects. However, when evaluated in clinical trials, the effects are variable, preliminary, or limited in magnitude. Fecal microbiota transplantation is another emerging therapy that regulates inflammation in experimental models. In human subjects it has been successfully used in cases of Clostridium difficile infection and IBD, although controlled trials are lacking for IBD. Here we discuss relationships between gut colonization and inflammatory NCDs and gut microbiota modulation strategies for their treatment and prevention.
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| 6. |
- West, Christina E., et al.
(författare)
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The gut microbiota and its role in the development of allergic disease: a wider perspective
- 2015
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Ingår i: Clinical and Experimental Allergy. - : Wiley: 12 months. - 0954-7894 .- 1365-2222. ; 45:1, s. 43-53
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Forskningsöversikt (refereegranskat)abstract
- The gut microbiota are critical in the homoeostasis of multiple interconnected host metabolic and immune networks. If early microbial colonization is delayed, the gut-associated lymphoid tissues (GALT) fail to develop, leading to persistent immune dysregulation in mice. Microbial colonization has also been proposed as a major driver for the normal age-related maturation of both Th1 and T regulatory (Treg) pathways that appear important in suppressing early propensity for Th2 allergic responses. There is emerging evidence that resident symbionts induce tolerogenic gut-associated Treg cells and dendritic cells that ensure the preferential growth of symbionts; keeping pathogenic strains in check and constraining proinflammatory Th1, Th2, and Th17 clones. Some effects of symbionts are mediated by short-chain fatty acids, which play a critical role in mucosal integrity and local and systemic metabolic function and stimulate the regulatory immune responses. The homoeostatic IL-10/TGF- dominated tolerogenic response within the GALT also signals the production of secretory IgA, which have a regulating role in mucosal integrity. Contrary to the sterile womb paradigm, recent studies suggest that maternal microbial transfer to the offspring begins during pregnancy, providing a pioneer microbiome. It is likely that appropriate microbial stimulation both pre- and postnatally is required for optimal Th1 and Treg development to avoid the pathophysiological processes leading to allergy. Disturbed gut colonization patterns have been associated with allergic disease, but whether microbial variation is the cause or effect of these diseases is still under investigation. We are far from understanding what constitutes a healthy gut microbiome that promotes tolerance. This remains a major limitation and might explain some of the inconsistency in human intervention studies with prebiotics and probiotics. Multidisciplinary integrative approaches with researchers working in networks, using harmonized outcomes and methodologies, are needed to advance our understanding in this field.
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