| 1. |
- Jakobsson, Hedvig E., et al.
(författare)
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Decreased gut microbiota diversity, delayed Bacteroidetes colonisation and reduced Th1 responses in infants delivered by Caesarean section
- 2014
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Ingår i: Gut. - London : BMJ. - 0017-5749 .- 1468-3288. ; 63:4, s. 559-566
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Tidskriftsartikel (refereegranskat)abstract
- important stimuli for immune development, and a reduced microbial exposure as well as caesarean section (CS) has been associated with the development of allergic disease. Here we address how microbiota development in infants is affected by mode of delivery, and relate differences in colonisation patterns to the maturation of a balanced Th1/Th2 immune response. Design The postnatal intestinal colonisation pattern was investigated in 24 infants, born vaginally (15) or by CS (nine). The intestinal microbiota were characterised using pyrosequencing of 16S rRNA genes at 1 week and 1, 3, 6, 12 and 24 months after birth. Venous blood levels of Th1- and Th2-associated chemokines were measured at 6, 12 and 24 months. Results Infants born through CS had lower total microbiota diversity during the first 2 years of life. CS delivered infants also had a lower abundance and diversity of the Bacteroidetes phylum and were less often colonised with the Bacteroidetes phylum. Infants born through CS had significantly lower levels of the Th1-associated chemokines CXCL10 and CXCL11 in blood. Conclusions CS was associated with a lower total microbial diversity, delayed colonisation of the Bacteroidetes phylum and reduced Th1 responses during the first 2 years of life.
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| 2. |
- Agreus, Lars, et al.
(författare)
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Towards a healthy stomach? : Helicobacter pylori prevalence has dramatically decreased over 23 years in adults in a Swedish community
- 2016
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Ingår i: United European Gastroenterology journal. - : Wiley. - 2050-6406 .- 2050-6414. ; 4:5, s. 686-696
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Tidskriftsartikel (refereegranskat)abstract
- Background In Western countries the prevalence of Helicobacter pylori (H. pylori) infection may be declining but there is a lack of recent longitudinal population studies. We evaluated the changing epidemiology over a 23-year period in Sweden.Materials and methods In 1989, the validated Abdominal Symptom Questionnaire (ASQ) was mailed to a random sample of inhabitants (ages 22-80 years) in a Swedish community, and 1097 (87%) responded. H. pylori serology was analysed in a representative subsample (n=145). Twenty-three years later, the ASQ was mailed again using similar selection criteria, and 388 out of 1036 responders had an upper endoscopy with assessment of H. pylori and corpus atrophy status.Results The prevalence of positive H. pylori serology decreased from 37.9% (1989) to 15.8% (2012), corresponding to a decrease in odds of 75% per decade (odds ratio (OR): 0.25; 95% confidence interval (CI): 0.11-0.59, p=0.001) independent of age, gender, body mass index (BMI) and level of education, with a pattern consistent with a birth cohort effect. The prevalence increased with increasing age (p=0.001). The prevalence of H. pylori on histology in 2012 was 11.4% (95% CI 8.6-15.0). The prevalence of corpus atrophy on serology and/or histology in 2012 was 3.2% (95% CI 1.8-5.5); all cases were 57 years old.Conclusion The stomach is healthier in 2012 compared with 1989. H. pylori prevalence in adults has decreased over the last two decades to a level where clinical management might be affected.
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| 3. |
- Basmarke-Wehelie, Rahma, et al.
(författare)
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The complement regulator CD46 is bactericidal to Helicobacter pylori and blocks urease activity
- 2011
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Ingår i: Gastroenterology. - Baltimore : Elsevier BV. - 0016-5085 .- 1528-0012. ; 141:3, s. 918-928
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: CD46 is a C3b/C4b binding complement regulator and a receptor for several human pathogens. We examined the interaction between CD46 and Helicobacter pylori (a bacterium that colonizes the human gastric mucosa and causes gastritis), peptic ulcers, and cancer.METHODS: Using gastric epithelial cells, we analyzed a set of H pylori strains and mutants for their ability to interact with CD46 and/or influence CD46 expression. Bacterial interaction with full-length CD46 and small CD46 peptides was evaluated by flow cytometry, fluorescence microscopy, enzyme-linked immunosorbent assay, and bacterial survival analyses.RESULTS: H pylori infection caused shedding of CD46 into the extracellular environment. A soluble form of CD46 bound to H pylori and inhibited growth, in a dose- and time-dependent manner, by interacting with urease and alkyl hydroperoxide reductase, which are essential bacterial pathogenicity-associated factors. Binding of CD46 or CD46-derived synthetic peptides blocked the urease activity and ability of bacteria to survive in acidic environments. Oral administration of one CD46 peptide eradicated H pylori from infected mice.CONCLUSIONS: CD46 is an antimicrobial agent that can eradicate H pylori. CD46 peptides might be developed to treat H pylori infection.
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| 4. |
- Björkqvist, Olle, 1993-, et al.
(författare)
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Alterations in the relative abundance of Faecalibacterium prausnitzii correlate with changes in fecal calprotectin in patients with ileal Crohn's disease : a longitudinal study
- 2019
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Ingår i: Scandinavian Journal of Gastroenterology. - : Taylor & Francis. - 0036-5521 .- 1502-7708. ; 54:4, s. 577-585
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Crohn's disease is characterized by a gut dysbiosis with decreased abundance of butyrate producers such as Faecalibacterium prausnitzii. Although F. prausnitzii secretes anti-inflammatory molecules, few studies have addressed the importance of F. prausnitzii in a longitudinal setting. We aimed to examine the relationship between temporal profiles of F. prausnitzii, the C. leptum group, overall butyrate production, and inflammatory activity.Material and methods: Fecal samples (n = 59) were collected every third month from nine patients with ileal Crohn's disease. The abundance of F. prausnitzii and C. leptum was quantified relative to the total amount of bacteria using quantitative-PCR. To assess butyrate production of gut microbiota, gene copy numbers of the butyryl-CoA:acetate-CoA transferase (BCoAT) gene were quantified by qPCR. The inflammatory activity was defined by fecal (f)-calprotectin.Results: No correlation between the relative abundance of F. prausnitzii, the C. leptum group, or copy numbers of the BCoAT gene, and f-calprotectin was observed in the total sample set. By analyzing alterations between consecutive samples, a negative correlation between changes in the relative abundance of F. prausnitzii and f-calprotectin was observed (R = -0.39; p = .009). Changes in C. leptum (R = -0.18, p = .23) and number of copies of the BCoAT gene (R = -0.12; p = .42) did not correlate with f-calprotectin.Conclusions: There was an inverse correlation between temporal changes in the relative abundance of F. prausnitzii, but not overall butyrate producing capacity, and changes in inflammatory activity in ileal Crohn's disease. These findings indicate that F. prausnitzii may play a role in gut homeostasis, even though causality is still to be demonstrated.
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| 5. |
- Carstens, Adam, 1975-, et al.
(författare)
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Differential clustering of faecal and mucosa-associated microbiota in healthy individuals
- 2018
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Ingår i: Journal of Digestive Diseases. - : Wiley-Blackwell Publishing Asia. - 1751-2972 .- 1751-2980. ; 19:12, s. 745-752
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Faecal samples are often used to characterise gut microbiota, since they are easily collected. However, whether or not the faecal microbiota differ from the mucosa-associated microbiota remains largely unknown. This may be specifically relevant in conditions that are characterised by complex mucosal microbe-host interactions, such as Crohn's disease. We aimed to determine the degree of agreement between faecal and mucosal microbiota profiles in healthy individuals, using two commonly used collection procedures.MATERIAL AND METHODS: The gut microbiota composition of faecal samples (sent at ambient temperature before storage at -70°C) and of colonic biopsies (obtained at endoscopy and immediately stored at -70°C) was determined by sequencing the 16S rRNA gene. Thirty-one randomly selected healthy individuals from the population-based colonoscopy (Popcol) study were included.RESULTS: Faecal samples were characterised by a reduced degree of richness (p<0.0001) and diversity (p=0.016), and also differences in several phyla, including a lower relative abundance of Proteobacteria (p<0.0001) and Verrucomicrobia (p=0.008) than in biopsies. Only 3 of 30 individuals had a similar faecal and mucosal microbiota profile, based on weighted UniFrac analysis. A difference in Crohn's disease dysbiosis-associated bacteria was observed, including a lower relative abundance of Faecalibacterium (p=0.004) and a higher relative abundance of Ruminococcus (p=0.001) in faeces than in biopsies.CONCLUSIONS: Analysis of faecal samples that have been transported at ambient temperature does not adequately reflect the colonic mucosa-associated microbiota in healthy individuals. These findings have implications for the interpretation of the previous literature, and may be specifically relevant to studies on Crohn's disease.
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| 6. |
- Carstens, Adam, 1975-, et al.
(författare)
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The Gut Microbiota in Collagenous Colitis Shares Characteristics With Inflammatory Bowel Disease-Associated Dysbiosis
- 2019
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Ingår i: Clinical and Translational Gastroenterology. - : Nature Publishing Group. - 2155-384X. ; 10:7
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: In inflammatory bowel disease (IBD), an aberrant immune response to gut microbiota is important, but the role of the microbiota in collagenous colitis (CC) is largely unknown. We aimed to characterize the microbiota of patients with CC compared with that of healthy control and patients with IBD.METHODS: Fecal samples were collected from patients with CC (n = 29), age- and sex-matched healthy controls (n = 29), patients with Crohn's disease (n = 32), and patients with ulcerative colitis (n = 32). Sequence data were obtained by 454 sequencing of 16S rRNA gene amplicons, and the obtained sequences were subsequently taxonomically classified.RESULTS: Analysis of similarity statistics showed a segregation between patients with CC and healthy controls with increasing taxonomic resolution, becoming significant comparing operational taxonomic unit data (P = 0.006). CC had a lower abundance of 10 different taxa. Taxa-specific analyses revealed a consistent lower abundance of several operational taxonomic units belonging to the Ruminococcaceae family in patients with CC, q < 0.05 after false discovery rate correction. Loss of these taxa was seen in patients with CC with active disease and/or corticosteroid treatment only and resembled the findings in patients with IBD.DISCUSSION: CC is associated with a specific fecal microbiome seen primarily in patients with active disease or ongoing corticosteroid treatment, whereas the microbiome of CC patients in remission resembled that of healthy controls. Notably, the shift in key taxa, including the Ruminococcaceae family, was also observed in IBD. There may be common mechanisms in the pathogenesis of CC and IBD.
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| 7. |
- Dlugosz, Aldona, et al.
(författare)
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No difference in small bowel microbiota between patients with irritable bowel syndrome and healthy controls
- 2015
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Several studies have indicated that colonic microbiota may exhibit important differences between patients with irritable bowel syndrome (IBS) and healthy controls. Less is known about the microbiota of the small bowel. We used massive parallel sequencing to explore the composition of small bowel mucosa-associated microbiota in patients with IBS and healthy controls. We analysed capsule biopsies from the jejunum of 35 patients (26 females) with IBS aged 18-(36)-57 years and 16 healthy volunteers (11 females) aged 20-(32)-48 years. Sequences were analysed based on taxonomic classification. The phyla with the highest total abundance across all samples were: Firmicutes (43%), Proteobacteria (23%), Bacteroidetes (15%), Actinobacteria (9.3%) and Fusobacteria (7.0%). The most abundant genera were: Streptococcus (19%), Veillonella (13%), Prevotella (12%), Rothia (6.4%), Haemophilus (5.7%), Actinobacillus (5.5%), Escherichia (4.6%) and Fusobacterium (4.3%). We found no difference among major phyla or genera between patients with IBS and controls. We identified a cluster of samples in the small bowel microbiota dominated by Prevotella, which may represent a common enterotype of the upper small intestine. The remaining samples formed a gradient, dominated by Streptococcus at one end and Escherichia at the other.
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| 8. |
- Engstrand Lilja, Helene, 1963-, et al.
(författare)
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Intestinal dysbiosis in children with short bowel syndrome is associated with impaired outcome
- 2015
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Ingår i: Microbiome. - : Springer Science and Business Media LLC. - 2049-2618. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- Background: The composition of the intestinal microbiota seems to be an important factor in determining the clinical outcome in children with short bowel syndrome (SBS). Alterations in the microbiota may result in serious complications such as small bowel bacterial overgrowth (SBBO) and intestinal mucosal inflammation that lead to prolonged parenteral nutrition (PN) dependency with subsequently increased risk of liver failure and sepsis. To date, there are no reported mappings of the intestinal microbiome in children with SBS. Here, we present the first report on the intestinal microbial community profile in children with SBS. Findings: The study includes children diagnosed with SBS in the neonatal period. Healthy siblings served as controls. Fecal samples were collected, and microbial profiles were analyzed by using 16S rRNA gene sequencing on the Illumina MiSeq platform. We observed a pronounced microbial dysbiosis in children with SBS on PN treatment with an increased and totally dominating relative abundance of Enterobacteriacae in four out of five children compared to children with SBS weaned from PN and healthy siblings. Conclusions: The overall decreased bacterial diversity in children with SBS is consistent with intestinal microbiome mappings in inflammatory bowel diseases such as Crohn's disease and necrotizing enterocolitis in preterm infants. Our findings indicate that intestinal dysbiosis in children with SBS is associated with prolonged PN dependency.
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