| 1. |
- Kennedy, K. M., et al.
(författare)
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Questioning the fetal microbiome illustrates pitfalls of low-biomass microbial studies
- 2023
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 613:7945, s. 639-649
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Tidskriftsartikel (refereegranskat)abstract
- Whether the human fetus and the prenatal intrauterine environment (amniotic fluid and placenta) are stably colonized by microbial communities in a healthy pregnancy remains a subject of debate. Here we evaluate recent studies that characterized microbial populations in human fetuses from the perspectives of reproductive biology, microbial ecology, bioinformatics, immunology, clinical microbiology and gnotobiology, and assess possible mechanisms by which the fetus might interact with microorganisms. Our analysis indicates that the detected microbial signals are likely the result of contamination during the clinical procedures to obtain fetal samples or during DNA extraction and DNA sequencing. Furthermore, the existence of live and replicating microbial populations in healthy fetal tissues is not compatible with fundamental concepts of immunology, clinical microbiology and the derivation of germ-free mammals. These conclusions are important to our understanding of human immune development and illustrate common pitfalls in the microbial analyses of many other low-biomass environments. The pursuit of a fetal microbiome serves as a cautionary example of the challenges of sequence-based microbiome studies when biomass is low or absent, and emphasizes the need for a trans-disciplinary approach that goes beyond contamination controls by also incorporating biological, ecological and mechanistic concepts.
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| 2. |
- Gore, C., et al.
(författare)
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Treatment and secondary prevention effects of the probiotics Lactobacillus paracasei or Bifidobacterium lactis on early infant eczema : randomized controlled trial with follow-up until age 3 years
- 2012
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Ingår i: Clinical and Experimental Allergy. - : Wiley. - 0954-7894 .- 1365-2222. ; 42:1, s. 112-122
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Tidskriftsartikel (refereegranskat)abstract
- Background Allergic disease has been associated with altered intestinal microbiota. Therefore, probiotics have been suggested as a potential treatment for eczema. Objective We investigated whether dietary supplementation of infants with eczema at age 3-6 months with Lactobacillus paracasei CNCM I-2116 or Bifidobacterium lactis CNCM I3446 had a treatment effect or altered allergic disease progression. Methods Primary outcome included eczema severity (SCORing Atopic Dermatitis, SCORAD) 3 months post-randomization. Secondary: SCORAD (other visits); infant dermatitis quality of life (IDQoL); gastrointestinal permeability; urinary eosinophilic protein X; allergen- sensitization; allergic symptoms (age 12, 18, 36 months). A total of 208 infants aged 3-6 months with physician-diagnosed eczema were recruited; 137/208 (SCORAD >= 10, consuming >= 200 mL standard formula/day) were randomized to daily supplements containing L. paracasei or B. lactis or placebo for a 3-month period, while receiving extensively hydrolysed whey-formula (dairy-free diet). There were two open observational groups, one group exclusively breastfed (n = 22) and the other, standard formula-fed (n = 49). Trial number: ISRCTN41490500. Results Eczema severity decreased significantly over time in all groups. No significant difference was observed between randomized groups after 12-week treatment-period (SCORAD-score pre-/post-intervention: B. lactis 25.9 [95% CI: 22.8-29.2] to 12.8 [9.416.6]; L. paracasei 25.4 [22.1-29] to 12.5 [9.2-16.4]; placebo 26.9 [23.4-30.6] to 11.8 [9.6-14.3]; P = 0.7). Results were similar when analysis was controlled for allergen-sensitization, or when only sensitized infants were analysed. No differences were found for secondary outcomes. No difference was observed in SCORAD-score between randomized and observational groups. Conclusion and Clinical Relevance We found no benefit from supplementation with B. lactis or L. paracasei in the treatment of eczema, when given as an adjunct to basic topical treatment, and no effect on the progression of allergic disease from age 1 to 3 years.
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| 3. |
- Fiocchi, Alessandro, et al.
(författare)
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Clinical Use of Probiotics in Pediatric Allergy (CUPPA) : A World Allergy Organization Position Paper
- 2012
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Ingår i: World Allergy Organization Journal. - 1939-4551. ; 5:11, s. 148-167
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Tidskriftsartikel (refereegranskat)abstract
- Background: Probiotic administration has been proposed for the prevention and treatment of specific allergic manifestations such as eczema, rhinitis, gastrointestinal allergy, food allergy, and asthma. However, published statements and scientific opinions disagree about the clinical usefulness.Objective: A World Allergy Organization Special Committee on Food Allergy and Nutrition review of the evidence regarding the use of probiotics for the prevention and treatment of allergy.Methods:A qualitative and narrative review of the literature on probiotic treatment of allergic disease was carried out to address the diversity and variable quality of relevant studies. This variability precluded systematization, and an expert panel group discussion method was used to evaluate the literature. In the absence of systematic reviews of treatment, meta-analyses of prevention studies were used to provide data in support of probiotic applications.Results:Despite the plethora of literature, probiotic research is still in its infancy. There is a need for basic microbiology research on the resident human microbiota. Mechanistic studies from biology, immunology, and genetics are needed before we can claim to harness the potential of immune modulatory effects of microbiota. Meanwhile, clinicians must take a step back and try to link disease state with alterations of the microbiota through well-controlled long-term studies to identify clinical indications.Conclusions:Probiotics do not have an established role in the prevention or treatment of allergy. No single probiotic supplement or class of supplements has been demonstrated to efficiently influence the course of any allergic manifestation or long-term disease or to be sufficient to do so. Further epidemiologic, immunologic, microbiologic, genetic, and clinical studies are necessary to determine whether probiotic supplements will be useful in preventing allergy. Until then, supplementation with probiotics remains empirical in allergy medicine. In the future, basic research should focus on homoeostatic studies, and clinical research should focus on preventive medicine applications, not only in allergy. Collaborations between allergo-immunologists and microbiologists in basic research and a multidisciplinary approach in clinical research are likely to be the most fruitful.
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| 4. |
- Tang, T., et al.
(författare)
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Biglycan deficiency: Increased aortic aneurysm formation and lack of atheroprotection
- 2014
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Ingår i: Journal of Molecular and Cellular Cardiology. - : Elsevier BV. - 0022-2828. ; 75, s. 174-180
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Tidskriftsartikel (refereegranskat)abstract
- Proteoglycans of the arterial wall play a critical role in vascular integrity and the development of atherosclerosis owing to their ability to organize extracellular matrix molecules and to hind and retain atherogenic apolipoprotein (apo)-B containing lipoproteins. Prior studies have suggested a role for biglycan in aneurysms and in atherosclerosis. Angiotensin II (angII) infusions into mice have been shown to induce abdominal aortic aneurysm development, increase vascular biglycan content, increase arterial retention of lipoproteins, and accelerate atherosclerosis. The goal of this study was to determine the role of biglycan in angII-induced vascular diseases. Biglycan-deficient or biglycan wildtype mice crossed to LDL receptor deficient (Ldlr-/-) mice (C57BL/6 background) were infused with angII (500 or 1000 ng/kg/min) or saline for 28 days while fed on normal chow, then pumps were removed, and mice were switched to an atherogenic Western diet for 6 weeks. During angII infusions, biglycan-deficient mice developed abdominal aortic aneurysms, unusual descending thoracic aneurysms, and a striking mortality caused by aortic rupture (76% for males and 48% for females at angII 1000 ng/kg/min). Histological analyses of non-aneurysmal aortic segments from biglycan-deficient mice revealed a deficiency of dense collagen fibers and the aneurysms demonstrated conspicuous elastin breaks. AngII infusion increased subsequent atherosclerotic lesion development in both biglycan-deficient and biglycan wildtype mice. However, the biglycan genotype did not affect the atherosclerotic lesion area induced by the Western diet after treatment with angII. Biglycan-deficient mice exhibited significantly increased vascular perlecan content compared to biglycan wildtype mice. Analyses of the atherosclerotic lesions demonstrated that vascular perlecan co-localized with apoB, suggesting that increased perlecan compensated for biglycan deficiency in terms of lipoprotein retention. Biglycan deficiency increases aortic aneurysm development and is not protective against the development of atherosclerosis. Biglycan deficiency leads to loosely packed aortic collagen fibers, increased susceptibility of aortic elastin fibers to angII-induced stress, and up-regulation of vascular perlecan content. Published by Elsevier Ltd.
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