| 1. |
- Ahlberg, Emelie, et al.
(författare)
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Immune-related microRNAs in breast milk and their relation to regulatory T cells in breastfed children
- 2023
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Ingår i: Pediatric Allergy and Immunology. - : Munksgaard Forlag. - 0905-6157 .- 1399-3038. ; 34:4
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The immunomodulatory capacity of breast milk may partially be mediated by microRNAs (miRNA), small RNA molecules that regulate gene expression on a post-transcriptional level and are hypothesized to be involved in modulation of immunological pathways. Here, we evaluate the expression of immune-related miRNAs in breast milk after pre- and postnatal supplementation with Limosilactobacillus reuteri and omega-3 (ω-3) polyunsaturated fatty acids (PUFAs), and the association to infant regulatory T cell (Treg) frequencies.METHODS: One-hundred and twenty women included in a double-blind, randomized, placebo-controlled allergy intervention trial received L. reuteri and/or ω-3 PUFAs daily from gestational week 20. Using Taqman qPCR, 24 miRNAs were analyzed from breast milk obtained at birth (colostrum) and after 3 months (mature milk) of lactation. The proportion of activated and resting Treg cells were analyzed in infant blood using flow cytometry at 6, 12, and 24 months.RESULTS: Relative expression changed significantly over the lactation period for most of the miRNAs; however, the expression was not significantly influenced by any of the supplements. Colostrum miR-181a-3p correlated with resting Treg cell frequencies at 6 months. Colostrum miR-148a-3p and let-7d-3p correlated with the frequencies of activated Treg cells at 24 months, as did mature milk miR-181a-3p and miR-181c-3p.CONCLUSION: Maternal supplementation with L. reuteri and ω-3 PUFAs did not significantly affect the relative miRNA expression in breast milk. Interestingly, some of the miRNAs correlate with Treg subpopulations in the breastfed children, supporting the hypothesis that breast milk miRNAs could be important in infant immune regulation. TRIAL REGISTRATION: ClinicalTrials.gov-ID: NCT01542970.
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| 2. |
- Martí Generó, Magalí Martí, et al.
(författare)
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Effects of Lactobacillus reuteri supplementation on the gut microbiota in extremely preterm infants in a randomized placebo-controlled trial
- 2021
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Ingår i: Cell Reports Medicine. - : Cell Press. - 2666-3791. ; 2:3
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Tidskriftsartikel (refereegranskat)abstract
- Extremely low birth weight (ELBW) infants often develop an altered gut microbiota composition, which is related to clinical complications, such as necrotizing enterocolitis and sepsis. Probiotic supplementation may reduce these complications, and modulation of the gut microbiome is a potential mechanism underlying the probiotic effectiveness. In a randomized, double-blind, placebo-controlled trial, we assessed the effect of Lactobacillus reuteri supplementation, from birth to post-menstrual week (PMW)36, on infant gut microbiota. We performed 16S amplicon sequencing in 558 stool samples from 132 ELBW preterm infants at 1 week, 2 weeks, 3 weeks, 4 weeks, PMW36, and 2 years. Probiotic supplementation results in increased bacterial diversity and increased L. reuteri abundance during the 1st month. At 1 week, probiotic supplementation also results in a lower abundance of Enterobacteriaceae and Staphylococcaceae. No effects were found at 2 years. In conclusion, probiotics may exert benefits by modulating the gut microbiota composition during the 1st month in ELBW infants.
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| 3. |
- Martí Generó, Magalí Martí
(författare)
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Magali Marti
- 2022
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Ingår i: Cell Reports Medicine. - : ELSEVIER. - 2666-3791. ; 3:4
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Magali Marti aims to improve infant health by modulation of the gut microbiome with probiotic and prebiotics. She studies how supplementation-induced changes in the microbiome-immune crosstalk affect growth, allergy prevention, and cognitive development. In this Q&A, she discusses her research, views, challenges, and the future of her field.
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| 4. |
- Generó, Magalí Martí, 1983-, et al.
(författare)
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A protocol for characterization of extremely preterm infant gut microbiota in double-blind clinical trials
- 2021
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Ingår i: STAR Protocols. - Cambridge, MA, United States : Cell press. - 2666-1667. ; 2:3
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Tidskriftsartikel (refereegranskat)abstract
- 16S rRNA gene sequencing enables microbial community profiling, but recovering fecal DNA from extremely premature infants is challenging. Here, we describe an optimized protocol for fecal DNA isolation, library preparation for 16S rRNA gene sequencing, taxonomy assignation, and statistical analyses. The protocol is complemented with a quantitative PCR for probiotic L. reuteri identification. This protocol describes how to characterize preterm infant gut microbiota and relate it to probiotic supplementation and clinical outcomes. It is customizable for other clinical trials. For complete details on the use and execution of this protocol, please refer to Martí et al. (2021) and Spreckels et al. (2021).
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| 5. |
- Genero, Magalí Martí
(författare)
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Microbial Communities in Boreal Peatlands : Responses to Climate Change and Atmospheric Nitrogen and Sulfur Depositions
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Myrmarker har en stor roll i regleringen av den globala kolbalansen och koncentrationerna av koldioxid och metan i atmosfären, vilket gör dem till speciellt viktiga ekosystem ur ett klimatförandringsperspektiv. Förändringar av myrmarker genom naturlig utveckling eller antropogen påverkan kan därför få långtgående störningar av myrars klimatreglerande funktion. Mikroorganismer har en avgörande roll i biogeokemiska processer genom att t ex bryta ned organisk material i mark och därmed styra kolets kretslopp. För att förstå hur myrsystemen reagerar på störningar är det därför väsentligt att veta hur mikroorganismsamhällena reagerar genom förändringar i sammansättning och biogeokemisk aktivitet. Målet för studierna, som ligger till grund för denna avhandling, var att undersöka hur mikroorganismsamhällen i myrar reagerar på uppvärmning genom klimatförändring och ökade kväve- (N) och svavel- (S) halter i nederbörd. High through-put sekvensering användes för att studera taxonomiska och funktionella egenskaper hos mikroorganismerna i myrar och quantative PCR användes för att mer specifikt studera de metanbildande arkeorna. Två fältkampanjer vardera omfattande tre ombrotrofa myrar med olika klimatförhållanden och olika mängder N och S inederbörden användes för att undersöka lokala och storskaliga effekter på myrars mikrobiella samhällen. Resultaten visade att latudinell variation i geoklimatologiska förhållanden (temperatur ochnederbördsmängd) och deposition av näringsämnen hade en påverkan på sammansättningen av de mikrobiella samhällena och aktiva metanbildare förr än variationen i den kemiska miljön inom varje specifik myr. Myrväxtsamhällenas sammansättning för en specifik myr visades sig i stor utsträckning styra sammansättningen av motsvarande mikrobiella samhälle i torvprofilen. Detta framgick klart av i en analys av samexisterande nätverk av mikroorganismsamhällen och motsvarande växtsamhällen i en studie av tre geografiskt skilda myrar med olika kvävedeposition. Effekterna av klimatförändring och nederbörd med olika mängder av N och S studerades mer specifikt genom att analysera de mikrobiellasamhällena i ett långliggande (18 år) försök. Påverkan av var och en av dessa manipulationer antingen förstärktes eller minskades, när de förekom i kombinationer. Ökad kvävedeposition var den faktor som hade starkast effekt. De långvariga störningarna medförde stora förändringar i den mikrobiella taxonomin inom samhällena. Detta återspeglades dock inte i den fysiologiska kapaciteten, vilket visar att det finns en stark buffring i myrarnas mikrobiella funktion. Detta tyder på att framtida utveckling av myrar i relation till olika störningar sannolikt inte kommer att påverka myrarnas roll för kolbalans och växthusgasutbyte med atmosfären.
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| 6. |
- Generó, Magalí Martí, 1983-, et al.
(författare)
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Nitrogen and methanogen community composition within and among three Sphagnum dominated peatlands in Scandinavia
- 2015
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Ingår i: Soil Biology and Biochemistry. - : Elsevier BV. - 0038-0717 .- 1879-3428. ; 81, s. 204-211
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Ombrotrophic raised bogs are nutrient poor acidic peatlands accumulating organic matter. They are widely spread on northern latitudes and are substantial sources of methane emissions to the atmosphere being of great concern from a climate change perspective. We investigated the methanogen community composition along microtopographic gradients within three bogs in Scandinavia, receiving different amounts of nitrogen precipitation. Methanogenic community analyses by terminal restriction fragment length polymorphism of the mcrA gene showed different profiles among the three sites, while no influence of the microtopographic gradients was observed. Peat temperature and dissolved organic carbon were the major edaphic variables explaining 38% of the variation of the methanogenic community diversity among the bogs. The family Methanoregulaceae (hydrogenotrophic methanogens) showed the largest relative proportion and highest activity in all three sites. Quantitative PCR of the mcrA gene and transcripts showed that the most northern site, receiving the lowest atmospheric nitrogen load, had significantly lower abundance and activity of methanogens (4.7 × 106 and 2.4 × 104 mcrA copies per gram of soil, respectively), compared to the most southern site (8.2 × 107 and 4.6 × 105 mcrA copies per gram of soil, respectively), receiving the highest nitrogen load. No patterns of the mcrA gene and transcript abundances were observed along the microtopography. The results indicated that the difference in occurrence of methanogens is mainly due to geoclimatological conditions rather than site intrinsic microtopographic variation. The study further suggests that environmental changes on the site intrinsic topography will not affect the methanogenic activity, while increasing average temperatures in Scandinavian ombrotrophic raised bogs might contribute to an increase of the methanogenic archaeal activity resulting in an increase of methane production.
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| 7. |
- Hellysaz, Arash, 1982-, et al.
(författare)
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Microbiota do not restrict rotavirus infection of colon
- 2023
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Ingår i: Journal of Virology. - : American Society for Microbiology. - 0022-538X .- 1098-5514. ; 97:11
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Tidskriftsartikel (refereegranskat)abstract
- Rotavirus is associated with extensive infection of the small intestine, whereas colon is considered to be uninfected. Considering that almost all bacteria in the gut colonize the colon, we hypothesized that the microbiota may act as a physical barrier preventing rotavirus infection in the colon in vivo. To address this hypothesis, we used human and mice colonoids, and biopsies of different intestinal segments of untreated and antibiotic-treated adult and infant mice. Rotavirus quantification was performed by qPCR and volumetric 3D imaging of intestinal segments. By 3D imaging, we observed infection in all the small intestinal segments, most extensively in the ileum, with most limited number of infected cells in colon. Broad-spectrum antibiotic treatment yielded no significant change in infection in either ileum or colon of adults and mice pups, although there is a substantial decrease in microbial load. We also show that rotavirus can successfully infect and replicate in colonoids from both mice and humans. Collectively, our data, including novel 3D imaging of the gut, mouse, and human colonoids, conclude that microbiota does not affect rotavirus infection in colon.IMPORTANCEAlterations of the gut microbiome can have significant effects on gastrointestinal homeostasis leading to various diseases and symptoms. Increased understanding of rotavirus infection in relation to the microbiota can provide better understanding on how microbiota can be used for clinical prevention as well as treatment strategies. Our volumetric 3D imaging data show that antibiotic treatment and its consequent reduction of the microbial load does not alter the extent of rotavirus infection of enterocytes in the small intestine and that restriction factors other than bacteria limit the infection of colonocytes.
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| 8. |
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| 9. |
- Moestedt, Jan, et al.
(författare)
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Effects of trace element addition on process stability during anaerobic co-digestion of OFMSW and slaughterhouse waste
- 2016
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Ingår i: Waste Management. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0956-053X .- 1879-2456. ; 47:Pt A, s. 11-20
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Tidskriftsartikel (refereegranskat)abstract
- This study used semi-continuous laboratory scale biogas reactors to simulate the effects of trace-element addition in different combinations, while degrading the organic fraction of municipal solid waste and slaughterhouse waste. The results show that the combined addition of Fe, Co and Ni was superior to the addition of only Fe, Fe and Co or Fe and Ni. However, the addition of only Fe resulted in a more stable process than the combined addition of Fe and Co, perhaps indicating a too efficient acidogenesis and/or homoacetogenesis in relation to a Ni-deprived methanogenic population. The results were observed in terms of higher biogas production (+9%), biogas production rates (+35%) and reduced VFA concentration for combined addition compared to only Fe and Ni. The higher stability was supported by observations of differences in viscosity, intraday WA-and biogas kinetics as well as by the 16S rRNA gene and 16S rRNA of the methanogens.(c) 2015 Elsevier Ltd. All rights reserved.
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| 10. |
- Robroek, Bjorn J. M., et al.
(författare)
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Microclimatological consequences for plant and microbial composition in Sphagnum-dominated peatlands
- 2014
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Ingår i: Boreal environment research. - Helsinki, Finland : Finnish Environment Institute. - 1239-6095 .- 1797-2469. ; 19:3, s. 195-208
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Tidskriftsartikel (refereegranskat)abstract
- In three Scandinavian peatlands we studied to what extent plant and microbial community compositions are governed by local-scale microhabitat, with a special interest in the effect of aspect (i.e. exposition of slopes). Despite differences in solar irradiance between the south- and north-facing slopes, maximum temperature was elevated in the south-facing slopes at the most northern site only. Pore-water nutrient concentrations were not affected by aspect, yet dissolved organic carbon concentrations were higher in the south-facing microhabitats. This was likely caused by higher vascular plant biomass. Plant and microbial community composition clearly differed among sites. In all three sites, microhabitat (i.e. prevailing water-table depth) affected the plant and microbial community compositions. Aspect, however, did not affect community composition, even though microclimate significantly differed between the south- and the north-facing aspects at the northernmost site. Our results highlight the complex link between plant community composition, microbial community and environmental conditions, which deserves much more attention than currently in order to fully understand the effects of climate change on peatland ecosystem function.
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