| 1. |
- Adawi, Diya, et al.
(författare)
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Safety of the probiotic strain Lactobacillus plantarum DSM 9843 (strain 299v) in an endocarditis animal model
- 2002
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Ingår i: Microbial Ecology in Health and Disease. - : Informa UK Limited. - 0891-060X .- 1651-2235. ; 14:1, s. 50-53
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Lactobacilli are often considered to be beneficial or non-pathogenic to man, with small numbers of human infections being reported, including septicemia and infective endocarditis. To verify the safety of Lactobacillus plantarum DSM 9843 (=strain 299v) administration, we used a well-known endocarditis animal model. Design: Experimental study using Sprague-Dawley rats. Setting: University Hospital, Sweden. Interventions: A catheter was passed down the right common carotid artery into the lumen of the left ventricle. The catheter was tied in place and the neck incision was closed. After 48 h, 0.5 ml of a bacterial suspension was injected through the tail vein. In the endocarditis control we inoculated Staphylococcus lugdunesis CCUG 25349T (T = type strain) and L. plantarum 299v was injected in the blood in L. plantarum group. Main outcome measures: Rats were sacrificed 96 h later and samples were taken from the heart, blood and catheter for bacterial culture and Randomly Amplified Polymorphic DNA (RAPD) evaluation. Results: L. plantarum 299v was injected in the blood but no lactobacilli were found in the heart, blood or catheter after 96 h. RAPD evaluation showed that S. lugdunesis CCUG 25349T was isolated from both blood and heart. Conclusion: The results showed that L. plantarum 299v has no role in the tested endocarditis animal model, which indicates the safety of L. plantarum 299v.
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| 2. |
- Adlerberth, Ingegerd, 1959, et al.
(författare)
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Gut microbiota and development of atopic eczema in 3 European birth cohorts.
- 2007
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Ingår i: The Journal of allergy and clinical immunology. - : Elsevier BV. - 0091-6749 .- 1097-6825. ; 120:2, s. 343-50
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Stimulation of the immune system by gut microbes might prevent allergy development. OBJECTIVE: The present study examined the hypothesis that sensitization to food allergens and atopic eczema are influenced by the infantile intestinal colonization pattern. METHODS: Infants were recruited perinatally in Göteborg (n = 116), London (n = 108), and Rome (n = 100). Commensal bacteria were identified to the genus or species level in rectal (3 days) and quantitative stool cultures (7, 14, and 28 days and 2, 6, and 12 months of age). At 18 months of age, atopic eczema and total and food-specific IgE levels were assessed. These outcomes were modeled in relation to time to colonization with 11 bacterial groups and to ratios of strict anaerobic to facultative anaerobic bacteria and gram-positive to gram-negative bacteria at certain time points. Study center, mode of delivery, parity, and infant diet were included as covariates. RESULTS: Neither atopic eczema nor food-specific IgE by 18 months of age were associated with time of acquisition of any particular bacterial group. Cesarean section delayed colonization by Escherichia coli and Bacteroides and Bifidobacterium species, giving way to, for example, Clostridium species. Lack of older siblings was associated with earlier colonization by Clostridium species and lower strict anaerobic/facultative anaerobic ratio at 12 months. CONCLUSIONS: This study does not support the hypothesis that sensitization to foods or atopic eczema in European infants in early life is associated with lack of any particular culturable intestinal commensal bacteria. CLINICAL IMPLICATIONS: The nature of the microbial stimulus required for protection from allergy remains to be identified.
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| 3. |
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| 4. |
- Ahrné, Siv, et al.
(författare)
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Development of immunocompetence: role of micronutrients and microorganisms
- 2002
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Ingår i: Nutritional Reviews. ; 60:Supplement 1, s. 68-72
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Tidskriftsartikel (refereegranskat)abstract
- Normal maturation of immune response at birth is both supported and stimulated by the gastrointestinal microenvironment, which provides both nutrients and antigenic microbial exposure to the developing child. Micronutrients, trace elements, and vitamins are present in the local environment and have important regulatory effects on adaptive immune cell function through effects on type of cytokine response. Congenital HIV infection is critically affected by both nutrient imbalance and alteration in gastrointestinal microflora, which may impair growth and development as well as immune response. Studies described here indicate that micronutrient deficiency is common in congenital HIV exposure even where infection has not occurred and that gastrointestinal recolonization may exert a restorative effect on both immune response and growth in children with HIV infection.
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| 5. |
- Ahrné, Siv, et al.
(författare)
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Effect of lactobacilli on paracellular permeability in the gut.
- 2011
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Ingår i: Nutrients. - : MDPI AG. - 2072-6643. ; 3:1, s. 104-117
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Tidskriftsartikel (refereegranskat)abstract
- Paracellular permeability is determined by the complex structures of junctions that are located between the epithelial cells. Already in 1996, it was shown that the human probiotic strain Lactobacillus plantarum 299v and the rat-originating strain Lactobacillus reuteri R2LC could reduce this permeability in a methotrexate-induced colitis model in the rat. Subsequently, many animal models and cell culture systems have shown indications that lactobacilli are able to counteract increased paracellular permeability evoked by cytokines, chemicals, infections, or stress. There have been few human studies focusing on the effect of lactobacilli on intestinal paracellular permeability but recently it has been shown that they could influence the tight junctions. More precisely, short-term administration of L. plantarum WCSF1 to healthy volunteers increased the relocation of occludin and ZO-1 into the tight junction area between duodenal epithelial cells.
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| 6. |
- Ahrné, Siv, et al.
(författare)
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Lactobacilli in the intestinal microbiota of Swedish infants
- 2005
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Ingår i: Microbes and Infection. - : Elsevier BV. - 1286-4579 .- 1769-714X. ; 7:11-12, s. 1256-62
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Tidskriftsartikel (refereegranskat)abstract
- Lactobacillus colonisation was examined in 112 Swedish infants. Faecal samples obtained at 1, 2, 4 and 8 weeks and at 6, 12 and 18 months of age were cultivated quantitatively on Rogosa agar. Lactobacilli were speciated by PCR and typed to the strain level by randomly amplified polymorphic DNA (RAPD). Lactobacilli reached a peak at 6 months when 45% of the infants were colonised. L. rhamnosus and L. gasseri were the most common species in this period. Colonisation by lactobacilli in general (P < 0.01) and L. rhamnosus in particular (P < 0.05) was more common in breast-fed than in weaned infants at 6 months of age. Lactobacillus isolation reached a nadir of 17% by 12 months (P < 0.0001), but increased to 31% by 18 months of age P < 0.05). The food-related species L. paracasei, L. plantarum, L. acidophilus and L. delbrueckii dominated in this second phase. A single strain persisted for at least 3 weeks in 17% of the infants during the first 6 months, most commonly L. rhamnosus. Lactobacillus population counts in colonised infants increased from 10(6.4) cfu/g at 1 week to 10(8.8) cfu/g at 6 months, and then dropped to 10(5.4) cfu/g faeces at 12 months of age. Lactobacillus colonisation was not significantly related to delivery mode, or to presence of siblings or pets in the household. Our results suggest that certain Lactobacillus species, especially L. rhamnosus, thrive in the intestinal flora of breast-fed infants. After weaning they are replaced by other Lactobacillus species of types found in food.
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| 7. |
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| 8. |
- Ahrné, Siv, et al.
(författare)
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The normal Lactobacillus flora of healthy human rectal and oral mucosa.
- 1998
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Ingår i: Journal of applied microbiology. - 1364-5072. ; 85:1, s. 88-94
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Tidskriftsartikel (refereegranskat)abstract
- The Lactobacillus flora of the rectal and oral mucosa was sampled from 42 healthy volunteers. Species identification was carried out by numerically comparing API 50CH fermentation patterns with type strains, using an SJ-similarity cut-off level of 79%. For the largest groups, identity was further confirmed by DNA-DNA hybridizations against the type strain of the species. Seventeen lactobacilli clusters were defined, of which most were found both on rectal and oral mucosa. The largest taxa were Lactobacillus plantarum, Lact. rhamnosus and Lact. paracasei ssp. paracasei, which were isolated from 52%, 26% and 17% of the individuals, respectively. Most isolates were tested for their capacity to adhere to the human colonic cell line HT-29 in the absence and presence of methyl-alpha-D-mannoside. Mannose-sensitive adherence to HT-29 cells was encountered in two-thirds of the Lact. plantarum isolates, but infrequently among isolates of other taxa. The results suggest that Lact. plantarum is a major colonizer of the human gastrointestinal mucosa, and that its capacity to adhere to mannose-containing receptors may be of some ecological importance.
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| 9. |
- Alam, Mehboob, et al.
(författare)
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Prevalence of Escherichia coli O157:H7 on spinach and rocket as affected by inoculum and time to harvest
- 2014
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Ingår i: Scientia Horticulturæ. - : Elsevier BV. - 0304-4238 .- 1879-1018. ; 165, s. 235-241
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Tidskriftsartikel (refereegranskat)abstract
- Irrigation water is an important vehicle for dissemination of human pathogens to plants. As contamination in an early stage of the production chain cannot necessarily be counteracted later, cultural measures to reduce the contamination risk need to be adopted during primary production. In a two-factorial greenhouse experiment, we studied the impact of inoculum density and the interval between irrigation and haivest on the prevalence of an inoculated gfp-tagged non-pathogenic strain of Escherichia coli O157:H7. The strain was inoculated with the irrigation water at a density of log 5.6, log 6.6 and log 7.6 CFU ml(-1) into the phyllosphere of fully grown crops of rocket and spinach (BBCH 49). The crops were then harvested after 3, 24,48 and 72 h. The introduced strain decreased exponentially in numbers within 72 h, to 49.6%, 52.6% and 50.6%, respectively, in the spinach and to 58.5%, 67.4% and 73.4% in the rocket. No differences were found in the number of the total viable count of aerobic bacteria and of Enterobacteriaceae as assessed on tryptic soy agar (TSA) and violet red bile dextrose agar (VRBD), respectively. Sequencing of the 16S rRNA genes of randomly selected isolates from VRBD were identified as Enterobacter cloaceae, Enterobacter ludwigii, Pantoea sp. and Raoultella planticola as the dominant Enterobacteriaceae species in the rocket and spinach phyllosphere. We found that cessation of irrigation for three days seems not to be an adequate sanitisation treatment to exclude the possibility of viable E. coil 0157:H7 cells on spinach or rocket. (C) 2013 Elsevier B.V. All rights reserved.
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| 10. |
- 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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