| 1. |
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| 2. |
- Andersson, Hannah, et al.
(författare)
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Oral Administration of Lactobacillus plantarum 299v Reduces Cortisol Levels in Human Saliva during Examination Induced Stress : A Randomized, Double-Blind Controlled Trial
- 2016
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Ingår i: International Journal of Microbiology. - : Hindawi Publishing Corporation. - 1687-918X .- 1687-9198. ; 2016
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To clarify the effect of Lactobacillus plantarum 299v on the salivary cortisol and salivary IgA levels in young adults under examination stress. Design. Forty-one students with an upcoming academic exam were included in a randomized double-blind, placebo-controlled study. The probiotic bacteria or the placebo product was administered in capsules once a day during 14 days. Saliva was collected and a perceived stress test was filled out at each sampling occasion. Saliva was collected for cortisol analysis by Electrochemiluminescence Immunoassay (ECLI) and salivary IgA was analysed by Enzyme-Linked Immunosorbent Assay (ELISA). Abundance of lactobacilli was evaluated by cultivation of saliva on selective medium and identification of L. plantarum 299v was done on randomly selected colonies by a random amplification of polymorphic DNA (RAPD) typing. Results. A significant difference in cortisol levels was found between the treatment group and the placebo group (P < 0.05), together with a significant increase in levels of lactobacilli in the treatment group compared with the placebo group (P < 0.001). No significant changes were found for salivary IgA. Conclusion. A probiotic bacterium with ability to reduce symptoms of irritable bowel syndrome (IBS) prohibited increased levels of the stress marker cortisol during the examination period. The registration number of the study is NCT02974894, and the study is registered at ClinicalTrials.gov.
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| 3. |
- Holst, Bjørn, et al.
(författare)
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Molecular switch controlling expression of the mannose-specific adhesin, Msa, in Lactobacillus plantarum
- 2019
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Ingår i: Applied and Environmental Microbiology. - 0099-2240. ; 85:10
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Tidskriftsartikel (refereegranskat)abstract
- Some lactic acid bacteria, especially Lactobacillus spp., possess adhesive properties enabling colonization of the human gastrointestinal tract. Two probiotic Lactobacillus plantarum strains, WCSF1 and 299v, display highly different mannose-specific adhesion, with L. plantarum 299v being superior to L. plantarum WCFS1 based on a yeast agglutination assay. A straightforward correlation between the mannose adhesion capacity and domain composition of the mannose-specific adhesin (Msa) in the two strains has not been demonstrated previously. In this study, we analyzed the promoter regions upstream of the msa gene encoding a mannose-specific adhesin in these two strains. The promoter region was mapped by primer extension and DNA sequence analysis, and only a single nucleotide change was identified between the two strains. However, Northern blot analysis showed a stronger msa transcript band in 299v than in WCFS1 correlating with the different adhesion capacities. During the establishment of a high-throughput yeast agglutination assay, we isolated variants of WCFS1 that displayed a very strong mannose-specific adhesion phenotype. The region upstream of the msa gene in these variants showed an inversion of a 104-bp fragment located between two perfectly inverted repeats present in the untranslated leader region. The inversion disrupts a strong hairpin structure that otherwise most likely would terminate the msa transcript. In addition, the ribosome binding site upstream of the msa gene, which is also masked within this hairpin structure, becomes accessible upon inversion, thereby increasing the frequency of translation initiation in the variant strains. Furthermore, Northern blot analysis showed a higher abundance of the msa transcript in the variants than in the wild type, correlating with a strong-Msa phenotype.
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| 4. |
- Håkansson, Åsa, et al.
(författare)
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Immunological alteration and changes of gut microbiota after dextran sulfate sodium (DSS) administration in mice
- 2015
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Ingår i: Clinical and Experimental Medicine. - : Springer Science and Business Media LLC. - 1591-9528. ; 15:1, s. 107-120
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Tidskriftsartikel (refereegranskat)abstract
- Ulcerative colitis (UC) is characterized bychronic inflammation of the colonic mucosa. Administrationof dextran sulfate sodium (DSS) to animals is a frequentlyused model to mimic human colitis. Deregulationof the immune response to the enteric microflora orpathogens as well as increased intestinal permeability havebeen proposed as disease-driving mechanisms. To enlargethe understanding of the pathogenesis, we have studied theeffect of DSS on the immune system and gut microbiota inmice. Intestinal inflammation was verified through histologicalevaluation and myeloperoxidase activity. Immunologicalchanges were assessed by flow cytometry inspleen, Peyer0s patches and mesenteric lymph nodes andthrough multiplex cytokine profiling. In addition, quantificationof the total amount of bacteria on colonic mucosaas well as the total amount of lactobacilli, Akkermansia,Desulfovibrio and Enterobacteriaceae was performed bythe use of quantitative PCR. Diversity and communitystructure were analysed by terminal restriction fragmentlength polymorphism (T-RFLP) patterns, and principalcomponent analysis was utilized on immunological andT-RFLP patterns. DSS-induced colitis show clinical andhistological similarities to UC. The composition of thecolonic microflora was profoundly changed and correlatedwith several alterations of the immune system. The resultsdemonstrate a relationship between multiple immunologicalchanges and alterations of the gut microbiota after DSSadministration. These data highlight and improve the definitionof the immunological basis of the disease andsuggest a role for dysregulation of the gut microbiota in thepathogenesis of colitis.
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| 5. |
- Linninge, Caroline, et al.
(författare)
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Effects of acute stress provocation on cortisol levels, zonulin and inflammatory markers in low- and high-stressed men
- 2018
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Ingår i: Biological Psychology. - : Elsevier BV. - 0301-0511 .- 1873-6246. ; 138, s. 48-55
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Tidskriftsartikel (refereegranskat)abstract
- The virtual version of the Trier Social Stress Test (V-TSST) is an effective and standardized tool for social stress induction. This study aimed to examine gut permeability and physiological and inflammatory markers of reactivity to acute psychosocial stress. Forty young men were classified as high-stressed (HIGHS) or low-stressed (LOWS) according to the Shirom-Melamed Burnout Questionnaire. Cardiovascular reactivity and gut dysfunction were studied along with cortisol, zonulin and cytokines. Gut permeability was shown to be affected within one hour after the psychosocial stress induction, and shown to be dependent on age. Interleukin-6 increased with time, most pronounced at the end of the one-hour recovery after V-TSST, and was positively correlated to age. HIGHS experienced more abdominal dysfunction compared to LOWS. In conclusion, this study is the first to show fluctuations in gut permeability after psychosocial stress induction. This was partly associated with changes in inflammatory markers.
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| 6. |
- Linninge, Caroline, et al.
(författare)
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Pre-treatment with antibiotics and Escherichia coli to equalize the gut microbiota in conventional mice.
- 2015
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Ingår i: Antonie van Leeuwenhoek. - : Springer Science and Business Media LLC. - 1572-9699 .- 0003-6072. ; 107:1, s. 149-156
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Tidskriftsartikel (refereegranskat)abstract
- The composition of the gut microbiota can vary widely between individual mice of the same batch and thereby affect the resulting outcome in experimental studies. Therefore, an efficient method is needed to equalize the gut microbiota prior to the start of critical experiments. In order to minimize variations in gut microbiota between animals and provide the animals with a Gram-negative flora exposing lipopolysaccharides in the cell-walls, C57BL/6 mice were given a mixture of ampicillin, metronidazole and clindamycin in the drinking water for 3 days and then Escherichia coli for two additional days. Treatment with antibiotics alone or with antibiotics in combination with E. coli was well tolerated by all animals. Body weight and liver weight were not affected, although higher hepatic fat content was found in treated animals (p < 0.05). The diversity of the gut microbiota was strongly reduced in animals treated with antibiotics and antibiotics in combination with E. coli (p < 0.01), without affecting the total amount of bacteria. Cloned and sequenced 16S rRNA genes showed high presence of Enterobacteriaceae and Porphymonadaceae in the treated animals. Analysis with Principal Component Analysis gave a clear separation of the composition in microbiota between different treatment groups. The described treatment efficiently equalized the gut microbiota and provided the animals with a strong abundance of Enterobacteriaceae without changing the total load of bacteria. This is a straightforward, lenient and efficient method of pre-treatment to equalize the gut microbiota of mice as a starting procedure of animal studies.
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| 7. |
- Tulstrup, Monica Vera-Lise, et al.
(författare)
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Antibiotic Treatment Affects Intestinal Permeability and Gut Microbial Composition in Wistar Rats Dependent on Antibiotic Class.
- 2015
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:12
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Tidskriftsartikel (refereegranskat)abstract
- Antibiotics are frequently administered orally to treat bacterial infections not necessarily related to the gastrointestinal system. This has adverse effects on the commensal gut microbial community, as it disrupts the intricate balance between specific bacterial groups within this ecosystem, potentially leading to dysbiosis. We hypothesized that modulation of community composition and function induced by antibiotics affects intestinal integrity depending on the antibiotic administered. To address this a total of 60 Wistar rats (housed in pairs with 6 cages per group) were dosed by oral gavage with either amoxicillin (AMX), cefotaxime (CTX), vancomycin (VAN), metronidazole (MTZ), or water (CON) daily for 10-11 days. Bacterial composition, alpha diversity and caecum short chain fatty acid levels were significantly affected by AMX, CTX and VAN, and varied among antibiotic treatments. A general decrease in diversity and an increase in the relative abundance of Proteobacteria was observed for all three antibiotics. Additionally, the relative abundance of Bifidobacteriaceae was increased in the CTX group and both Lactobacillaceae and Verrucomicrobiaceae were increased in the VAN group compared to the CON group. No changes in microbiota composition or function were observed following MTZ treatment. Intestinal permeability to 4 kDa FITC-dextran decreased after CTX and VAN treatment and increased following MTZ treatment. Plasma haptoglobin levels were increased by both AMX and CTX but no changes in expression of host tight junction genes were found in any treatment group. A strong correlation between the level of caecal succinate, the relative abundance of Clostridiaceae 1 family in the caecum, and the level of acute phase protein haptoglobin in blood plasma was observed. In conclusion, antibiotic-induced changes in microbiota may be linked to alterations in intestinal permeability, although the specific interactions remain to be elucidated as changes in permeability did not always result from major changes in microbiota and vice versa.
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| 8. |
- Uhlig, Elisabeth, et al.
(författare)
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Effects of household washing on bacterial load and removal of Escherichia coli from lettuce and "ready-to-eat" salads
- 2017
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Ingår i: Food Science and Nutrition. - : Wiley. - 2048-7177. ; 5:6, s. 1215-1220
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Tidskriftsartikel (refereegranskat)abstract
- Customer demands for fresh salads are increasing, but leafy green vegetables have also been linked to food-borne illness due to pathogens such as Escherichia coli O157:H7. As a safety measure, consumers often wash leafy vegetables in water before consumption. In this study, we analyzed the efficiency of household washing to reduce the bacterial content. Romaine lettuce and ready-to-eat mixed salad were washed several times in flowing water at different rates and by immersing the leaves in water. Lettuce was also inoculated with E. coli before washing. Only washing in a high flow rate (8 L/min) resulted in statistically significant reductions (p < .05), "Total aerobic count" was reduced by 80%, and Enterobacteriaceae count was reduced by 68% after the first rinse. The number of contaminating E. coli was not significantly reduced. The dominating part of the culturable microbiota of the washed lettuce was identified by rRNA 16S sequencing of randomly picked colonies. The majority belonged to Pseudomonadaceae, but isolates from Enterobacteriaceae and Staphylococcaceaceae were also frequently found. This study shows the inefficiency of tap water washing methods available for the consumer when it comes to removal of bacteria from lettuce. Even after washing, the lettuce contained high levels of bacteria that in a high dose and under certain circumstances may constitute a health risk.
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| 9. |
- Xu, Jie, et al.
(författare)
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Oral and faecal microbiota in volunteers with hypertension in a double blind, randomised placebo controlled trial with probiotics and fermented bilberries
- 2015
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Ingår i: Journal of Functional Foods. - : Elsevier BV. - 1756-4646. ; 18, s. 275-288
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Tidskriftsartikel (refereegranskat)abstract
- Two probiotic products containing either live Lactobacillus plantarum strain DSM 15313 or bilberries fermented by the same bacterial strain were tested for their antihypertensive potentials and their impact on the oral and the faecal microbiota in hypertensive adults. The results showed that consumption of the tested products for three months did not reduce the blood pressure in adults with hypertension. Neither the diversity nor the composition of the oral and faecal microbiota was significantly affected by the tested probiotic products. Moreover, the oral and the faecal microbiota remained generally stable over the intervention period of 3 months. (C) 2015 Elsevier Ltd. All rights reserved.
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