Capability of exopolysaccharide-producing Lactobacillus paraplantarum BGCG11 and its non-producing isogenic strain NB1, to counteract the effect of enteropathogens upon the epithelial cell line HT29-MTX (original) (raw)
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Frontiers in Microbiology, 2016
The aim of this study was to determine the role of an exopolysaccharide produced by natural dairy isolate Lactobacillus paracasei subsp. paracasei BGSJ2-8, in the adhesion to intestinal epithelial cells and a decrease in Escherichia coli's association with Caco-2 cells. Annotation of the BGSJ2-8 genome showed the presence of a gene cluster, epsSJ, which encodes the biosynthesis of the strain-specific exopolysaccharide EPS-SJ, detected as two fractions (P1 and P2) by size exclusion chromatography (SEC) coupled with multi-angle laser light scattering (MALLS) detection. SEC-MALLS analysis revealed that an EPS-SJ − mutant (EPS7, obtained by insertion mutagenesis of the glps_2198 gene encoding primary glycosyltransferase) does not produce the P2 fraction of EPS-SJ. Transmission electron microscopy showed that EPS7 mutant has a thinner cell wall compared to the EPS-SJ + strain BGSJ2-83 (a plasmid freederivative of BGSJ2-8). Interestingly, strain BGSJ2-83 showed higher adhesion to Caco-2 epithelial intestinal cell line than the EPS7 mutant. Accordingly, BGSJ2-83 effectively reduced E. coli ATCC25922's association with Caco-2 cells, while EPS7 did not show statistically significant differences. In addition, the effect of EPS-SJ on the proliferation of lymphocytes in gastrointestinal associated lymphoid tissue (GALT) was tested and the results showed that the reduction of GALT lymphocyte proliferation was higher by BGSJ2-83 than by the mutant. To the best of our knowledge this is the first report indicating that the presence of EPS (EPS-SJ) on the surface of lactobacilli can improve communication between bacteria and intestinal epithelium, implying its possible role in gut colonization.
Journal of Food …, 2006
Exopolysaccharides (EPSs) are exocellular polymers present in the surface of many bacteria, including Lactobacillus and Bifidobacterium. The genome sequence of several strains revealed the presence of EPS-encoding genes. However, the physiological role that EPSs play in the bacterial ecology still remains uncertain. In this study, we have assessed the effect of EPSs produced by Lactobacillus rhamnosus GG, Bifidobacterium longum NB667, and Bifidobacterium animalis IPLA-R1 on the adhesion of probiotic and enteropathogen strains to human intestinal mucus. The EPS fraction GG had no significant effect on the adhesion of L. rhamnosus GG and B. animalis IPLA-R1. However, the EPS fractions NB667 and IPLA-R1 significantly reduced the adherence of both probiotic strains. In contrast, the three EPS fractions increased the adhesion of Enterobacter sakazakii ATCC 29544 and Escherichia coli NCTC 8603. Higher adherence of Salmonella enterica serovar Typhimurium ATCC 29631 and Clostridium difficile ATCC 9689 was detected in the presence of the EPS fractions GG and NB667. In general, these effects were obtained at EPS concentrations of up to 5 mg/ml, and they were EPS dose dependent. The competitive exclusion of probiotics in the presence of EPS could suggest the involvement of these biopolymers in the adhesion to mucus. The increase in the adherence of enteropathogens could be explained if components of the pathogen surface are able to bind to specific EPSs and the bound EPSs are able to adhere to mucus. To the best of our knowledge, this is the first work reporting the effect of EPSs from probiotics on bacterial adhesion properties.
Carbohydrate Polymers, 2016
The aim of the study was to characterize exopolysaccharides (EPS) originated from Lactobacillus reuteri strain DSM 17938 (EPS-DSM17938) and L. reuteri strain L26 Biocenol TM (EPS-L26) and evaluate their influence on adherence of enterotoxigenic Escherichia coli (ETEC) to IPEC-1 cells and proinflammatory gene expression. Both EPS were D-glucan polysaccharides with higher molecular weight (M w), but differing in spatial conformation and elicited variable cytokine profile. EPS-DSM17938, relatively linear polysaccharide with (1→4) and (1→6) glycosidic linkages, increased IL-1β gene expression (0.1 mg/mL; P < 0.05), while EPS-L26, more branched polysaccharide with (1→3) and (1→6) glycosidic linkages, exerted slight but statistically significant up-regulation of NF-κB, TNF-α and IL-6 mRNA (P < 0.05). The most significant finding is that preincubation of IPEC-1 cells with both EPS followed by ETEC infection inhibit ETEC adhesion on IPEC-1 cells (P < 0.01) and ETEC-induced gene expression of proinflammatory cytokine IL-1β and IL-6 (P < 0.01).
Journal of Food Science, 2010
A number of Lactobacillus species are used as probiotic strains in order to benefit health. We have isolated L. fermentum from human colonic mucosal biopsy samples that possess antimicrobial activities against entroinvasive and foodborne pathogens such as Escherichia coli, Salmonella paratyphi A, Shigella sonnei, Staphylococcus aureus, Enterococcus faecalis, Proteus mirabilis, Pseudomonas aeruginosa, and Vibrio sp. In addition to lactic acid, L. fermentum secretes antimicrobial proteinacious compound(s) that was found to be active even at neutral pH (pH 7.0). The compound was sensitive to heat treatment and trypsin digestion. Lactobacillus fermentum inhibited the adhesion of enteropathogens to intestinal epithelial cells in vitro. Isolated cell surface associated proteins (SAPs) from L. fermentum were sufficient for the adhesion exclusions of enteropathogenic E. coli. Our results indicate that L. fermentum produces antimicrobial compounds and SAPs to inhibit the growth and adhesion of enteropathogens, respectively.
Journal of dairy science, 2006
The strong ropy character of the Scandinavian fermented milk viili is conferred by the exopolysaccharides (EPS) produced by lactococcal strains. These biopolymers can be responsible for some health benefits. We have assessed the influence of the EPS fraction isolated from commercial viili on the adhesion of some probiotics and pathogens to human intestinal mucus. Concentrations of viili EPS greater than 0.1 mg/mL promoted a decrease in adherence of Bifidobacterium lactis Bb12 and Lactobacillus rhamnosus GG and this effect was dose-dependent. However, no modifications were detected on the adhesion levels of the pathogenic strains tested at a concentration of 1 mg/mL of EPS. Results obtained in the present work should be considered in the design of new probiotic products.
Food Research International, 2007
Competition with pathogens for adhesion and colonization of the mucosal surfaces are possible protective mechanisms of probiotics. In this study we evaluated the ability of commercial strains (Lactobacillus rhamnosus GG, L. rhamnosus LC705, B. breve 99 and Propionibacterium freudenreichii ssp. shermanii JS) each strain alone and in diVerent combinations to inhibit, displace and compete with selected pathogens in order to test the inXuence of the presence of the other probiotic in the adhesion pathogens to immobilized mucus. The ability to inhibit the adhesion or to displace adhered pathogens was variable depending on both the probiotic combination and the pathogen tested. Our results demonstrate that diVerent probiotic combinations were able to enhance the inhibition percentages to pathogen adhesion to intestinal mucus. All probiotic combinations tested in this study showed inhibition abilities against pathogen infection with values which were over 40% for some pathogens tested. Combinations had speciWc properties and inhibition abilities against some or all of the tested pathogens. These results suggest that combinations of probiotics strains could be useful and more eVective in inhibition of pathogen adhesion. The inhibition and displacement proWles were very diVerent suggesting that diVerent mechanisms are implied in both processes. Selection of new probiotic combinations should be conducted for speciWc target pathogens or pathogen associated microbiota aberrancies.
Evaluation of adhesion properties of lactobacilli probiotic candidates
Monatshefte für Chemie - Chemical Monthly
Bacterial adhesion is a complex phenomenon implicated in the host-bacterial interaction that is pivotal for probiotic activity. Eight probiotic lactobacilli candidates (Lactobacillus reuteri, L. plantarum, L. mucosae, L. murinus) were screened for their ability to adhere to abiotic and biotic surfaces in vitro. Adhesion to hydrocarbons was used for hydrophobicity assessment. Three strains of L. reuteri and L. murinus C were evaluated as hydrophobic, others as intermediate. All tested strains were able to form the biofilm on polystyrene. L. mucosae D and L. reuteri E were tested for adhesion to epithelial cell lines (HeLa and Caco-2). Both were more adherent to HeLa than to Caco-2. The adhesivity degree in HeLa reached the highest value after 8 h of co-cultivation in both lactobacilli tested, then decreased. In Caco-2, adhesion was increased within 24 h from the beginning of the co-cultivation. Mucus-binding protein gene, implicated in adhesion, was detected in L. mucosae D. Therefore, the involvement of proteinaceous substances in binding process was investigated. Cells of L. mucosae D were digested by three proteolytic enzymes (proteinase K, pronase E, trypsin) and evaluated for time-dependent adhesivity changes to HeLa, Caco-2, and L929 cell lines. Results confirmed that proteins are most likely to play an important role in binding of lactobacilli to eukaryotic cells. One hour after treatment, L. mucosae D was able to overcome the effect of proteolytic cleavage. We assume that it was due to the restoration of its cell-surface binding structures. Co-cultivation of HeLa and L. mucosae D led to protuberance and communication channels formation in eukaryotic cells.
Infection and Immunity, 2008
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 intimately attaches to intestinal epithelial monolayers and produces attaching and effacing (A/E) lesions. In addition, EHEC infection causes disruptions of intercellular tight junctions, leading to clinical sequelae that include acute diarrhea, hemorrhagic colitis, and the hemolytic-uremic syndrome. Current therapy remains supportive since antibiotic therapy increases the risk of systemic complications. This study focused on the potential therapeutic effect of an alternative form of therapy, probiotic Lactobacillus rhamnosus strain GG, to attenuate EHEC-induced changes in paracellular permeability in polarized MDCK-I and T84 epithelial cell monolayers. Changes in epithelial cell morphology, electrical resistance, dextran permeability, and distribution and expression of claudin-1 and ZO-1 were assessed using phase-contrast, immunofluorescence, and transmission electron microscopy and macromolecular flux. This study demonstrated that ...
2012
Traditional fermented foods are the best source for the isolation of strains with specific traits to act as functional starters and to keep the biodiversity of the culture collections. Besides, these strains could be used in the formulation of foods claimed to promote health benefits, i.e. those containing probiotic microorganisms. For the rational selection of strains acting as probiotics, several in vitro tests have been proposed. In the current study, we have characterised the probiotic potential of the strain Lactobacillus paraplantarum BGCG11, isolated from a Serbian soft, white, homemade cheese, which is able to produce a "ropy" exopolysaccharide (EPS). Three novobiocin derivative strains, which have lost the ropy phenotype, were characterised as well in order to determine the putative role of the EPS in the probiotic potential. Under chemically gastrointestinal conditions, all strains were able to survive around 1-2% (10 6-10 7 cfu/ml cultivable bacteria) only when they were included in a food matrix (1% skimmed milk). The strains were more resistant to acid conditions than to bile salts and gastric or pancreatic enzymes, which could be due to a pre-adaptation of the parental strain to acidic conditions in the cheese habitat. The ropy EPS did not improve the survival of the producing strain. On the contrary, the presence of an EPS layer surrounding the strain BGCG11 hindered its adhesion to the three epithelial intestinal cell lines tested, since the adhesion of the three non-ropy derivatives was higher than the parental one and also than that of the reference strain Lactobacillus rhamnosus GG. Aiming to propose a potential target application of these strains as probiotics, the cytokine production of peripheral blood mononuclear cells (PBMC) was analysed. The EPS-producing L. paraplantarum BGCG11 strain showed an anti-inflammatory or immunosuppressor profile whereas the non-ropy derivative strains induced higher pro-inflammatory response. In addition, when PBMC were stimulated with increasing concentrations of the purified ropy EPS (1, 10 and 100 g/ml) the cytokine profile was similar to that obtained with the EPS-producing lactobacilli, therefore pointing to a putative role of this biopolymer in its immune response.
Gut Microbes
Abstract Impaired gut barrier function has been reported in a wide range of diseases and syndromes and in some functional gastrointestinal disorders. In addition, there is increasing evidence that suggests the gut microbiota tightly regulates gut barrier function and recent studies demonstrate that probiotic bacteria can enhance barrier integrity. Here, we aimed to investigate the effects of Lactobacillus rhamnosus CNCM I-3690 on intestinal barrier function. In vitro results using a Caco-2 monolayer cells stimulated with TNF-α confirmed the anti-inflammatory nature of the strain CNCM I-3690 and pointed out a putative role for the protection of the epithelial function. Next, we tested the protective effects of L. rhamnosus CNCM I-3690 in a mouse model of increased colonic permeability. Most importantly, we compared its performance to that of the well-known beneficial human commensal bacterium Faecalibacterium prauznitzii A2-165. Increased colonic permeability was normalized by both s...