Exopolysaccharides have prebiotic potential and contribute to the rheology and texture of fermented foods. Here we have analyzed the in vitro bioavailability and immunomodulatory properties of the ...2-substituted (1,3)-β-D-glucan-producing bacterium Pediococcus parvulus 2.6. It resists gastrointestinal stress, adheres to Caco-2 cells, and induces the production of inflammation-related cytokines by polarized macrophages.
Biogenic amines in food constitute a human health risk. Here we report that tyramine-producing Enterococcus durans strain IPLA655 (from cheese) was able to produce tyramine under conditions ...simulating transit through the gastrointestinal tract. Activation of the tyramine biosynthetic pathway contributed to binding and immunomodulation of enterocytes.
A sea fennel (
) aqueous extract was prepared and loaded into soybean phosphatidylcholine liposomes. Both the free extract (FE), and the empty (L) and loaded (L-FE) liposomes were shown to be ...non-cytotoxic to THP-1 and Caco-2 cells. The anti-inflammatory effect was tested on THP-1 cells differentiated into macrophages. FE showed anti-inflammatory activity, revealed by the induced secretion of IL-10 cytokines in macrophages that were subsequently stimulated with LPS. Also, a decrease in TNF-α production by L was observed, evidencing that liposomes reduced the pro-inflammatory mediators' secretion. The liposomes (L) showed protective anti-inflammatory activity and also were able to downregulate the inflammation. Furthermore, L-FE were also found to downregulate the inflammation response, as they were able to decrease TNF-α secretion in macrophages previously exposed to LPS. The simulated in vitro gastrointestinal digestion (GID) of FE diminished the chlorogenic acid content (the main polyphenolic compound of the extract) by 40%, while in L-FE, the amount of this phenolic compound increased with respect to the undigested liposomes. The amount of bioaccessible chlorogenic, however, was similar for FE and L-FE. The percentage of chlorogenic acid absorbed through a Caco-2 cell monolayer after 3 h of incubation, was significantly similar for the extract and the liposomes (~1.5%), without finding significant differences once the extract and liposomes were digested.
Probiotics, prebiotics and synbiotics are frequently-used components for the elaboration of functional food. Currently, most of the commercialized probiotics are limited to a few strains of the ...genera Bifidobacteria, Lactobacillus and Streptococcus, most of which produce exopolysaccharides (EPS). This suggests that the beneficial properties of these microorganisms may be related to the biological activities of these biopolymers. In this work we report that a 2-substituted-(1,3)-β-d-glucan of non-dairy bacterial origin has a prebiotic effect on three probiotic strains. Moreover, the presence of this β-d-glucan potentiates in vitro adhesion of the probiotic Lactobacillus plantarum WCFS1 to human intestinal epithelial cells.
Vegetal waste materials were used to produce liposomes with both antioxidant and anti-inflammatory properties. Differences in the chemical composition of rapeseed lecithin (LEC) and a partially ...purified phospholipid fraction (PPL) were studied in terms of fatty acids (neutral lipids, free fatty acids, and phospholipids), sterols, tocopherols, and amino acid composition. Neutral lipids, campesterol, β-sitosterol, and γ-tocopherol were the most depleted compounds in PPL. Qualitative differences between LEC and PPL were revealed by infrared spectroscopy and differential scanning calorimetry. An ethanol/water antioxidant extract from chia seeds (ChE), with a high content in rosmarinic acid and rosmarinic acid 3-O-glucoside, along with other minor phenolic acids determined by HPLC-MS, was encapsulated in liposomes made of LEC (L-LEC) and PPL (L-PPL) with an entrapment efficiency of 61.3% and 69.3%, respectively. L-PPL suspensions showed smaller particle size and lower ζ potential than their L-LEC counterparts, along with noticeable particle destabilization after 7 days of storage. Antioxidant properties were greater in L-LEC than in L-PPL suspensions. L-LEC, ChE, and lecithin empty liposomes (L-E) showed no cytotoxic effect in either Caco-2 or THP-1 cells and induced downregulation of the inflammation response.
•We report an immunological method for detection of 2-substituted (1,3)-β-d-glucans.•The method can be used in the presence of other polysaccharides.•The method can quickly identify 2-substituted ...(1,3)-β-d-glucan producing bacteria.•The method can be used for the characterization of glycosyltransferases.
Exopolysaccharides synthesized by lactic acid bacteria have prebiotic properties and contribute to the rheology and texture of fermented foods. Here, we have standardized an immunological method for the specific detection of 2-substituted (1,3)-β-d-glucans. The method allows direct detection and quantification of this exopolysaccharide in culture supernatants containing other mono- and poly-saccharides. Moreover, it allows specific detection of the biomolecules synthesized in vitro in enzymatic reactions. Thus, this method allows the fast identification of producing bacteria, as well as biochemical characterization of the glycosyltransferases responsible for their synthesis.
Background Anisakis spp. are nematode parasites found in a wide range of marine organisms. Human beings may accidentally become infected, showing the symptoms of anisakiasis and allergic responses. ...There has been evidence of increased intestinal permeability in A. simplex-sensitized subjects and that specific IgE titres increase in some allergic patients when fishery products are re-introduced into their diet. The aims of this work were to study the effect of A. simplex crude extract on the intestinal integrity and permeability by using Caco-2 cell monolayer. To analyse the capacity of Ani s 4 allergen to cross the epithelial barrier. Methodology/Principal findings Cellular bioenergetics, transepithelial electrical resistance, viability, permeability, reactive oxygen species generation and immunofluorescent staining of tight junction proteins were analysed. A. simplex crude extract compromises the Caco-2 cell monolayer integrity in a dose-dependent manner. This effect is detected at 1 hour of culture and integrity is recovered after 24 hours of culture. The epithelial barrier disruption is accompanied by an increase in paracellular permeability and reactive oxygen species production and by a delocalization of occludin and zonula occludens-1. Finally, Ani s 4, a thermostable and resistant to digestion allergen with cystatin activity, is able to cross the epithelial barrier in Caco-2 monolayer and reach a cumulative mean percentage of 22.7% of total concentration in the basolateral side after 24 hours of culture. Conclusions/Significance Our results demonstrate that A. simplex induces an early and reversible alteration of integrity and permeability of Caco-2 cell monolayer and that an underlying mechanism of this effect would involve the oxidative stress and disruption of epithelial tight junctions. Additionally, it has been shown that Ani s 4 allergen is able to cross the epithelial barrier. These findings could explain the increased intestinal permeability observed in Anisakis-sensitized patients, the changes over time in IgE sensitization to A. simplex allergens, and the specific IgE persistence in Anisakis allergy.
Oenococcus oeni is the main lactic acid bacterium that carries out the malolactic fermentation in virtually all red wines and in some white and sparkling wines. Oenococcus oeni possesses an array of ...metabolic activities that can modify the taste and aromatic properties of wine. There is, therefore, industrial interest in the proteins involved in these metabolic pathways and related transport systems of this bacterium. In this work, we report the characterization of the O. oeni ATCC BAA-1163 proteome. Total and membrane protein preparations from O. oeni were standardized and analysed by two-dimensional gel electrophoresis. Using tandem mass spectrometry, we identified 224 different spots corresponding to 152 unique proteins, which have been classified by their putative function and subjected to bioinformatics analysis.
We have isolated three lactic acid bacteria (
Lactobacillus suebicus CUPV221,
Pediococcus parvulus CUPV1 and
P. parvulus CUPV22) that produced high levels of 2-substituted (1,3)-β-
d-glucans which ...increased the viscosity of the growth media. The (1,3)-β-
d-glucan consisted of two main molecular species, with masses of approximately 10
7 and 10
4
Da, whose proportions varied among the strains. The three strains survived exposure to saliva and simulated gastric conditions at pH 5, with
P. parvulus CUPV22 surviving at pH 3.1, and
L. suebicus CUPV221 surviving at pH 1.8. All strains were resistant to pancreatin and bile salts.
P. parvulus CUPV22 exhibited the highest adhesion (10.5%) to Caco-2 cells, which decreased to 1.2% after washing the cells. Finally,
P. parvulus CUPV22 and
L. suebicus CUPV221 induced the production of inflammation-related cytokines by polarized macrophages, and interestingly,
L. suebicus stimulated the production of cytokine IL-10. These results indicate that the three strains have potential utility for the production of functional foods.
Fluorescent reporter genes are valuable tools for real-time monitoring of gene expression in living cells. In this study we describe the construction of novel promoter-probe vectors containing a ...synthetic mCherry fluorescent protein gene, codon-optimized for lactic acid bacteria, divergently linked, or not, to a gene encoding the S65T and F64L variant of the green fluorescent protein. The utility of the transcriptional fusion vectors was demonstrated by the cloning of a single or two divergent promoter regions and by the quantitative evaluation of fluorescence during growth of
Lactococcus lactis
,
Enterococcus faecalis
, and
Escherichia coli
.
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