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Bernardo D.,Imperial College London | Sanchez B.,Institute Productos Lacteos Of Asturias | Al-Hassi H.O.,Imperial College London | Mann E.R.,Imperial College London | And 3 more authors.
PLoS ONE | Year: 2012

The human gastrointestinal tract is exposed to a huge variety of microorganisms, either commensal or pathogenic; at this site, a balance between immunity and immune tolerance is required. Intestinal dendritic cells (DCs) control the mechanisms of immune response/tolerance in the gut. In this paper we have identified a peptide (STp) secreted by Lactobacillus plantarum, characterized by the abundance of serine and threonine residues within its sequence. STp is encoded in one of the main extracellular proteins produced by such species, which includes some probiotic strains, and lacks cleavage sites for the major intestinal proteases. When studied in vitro, STp expanded the ongoing production of regulatory IL-10 in human intestinal DCs from healthy controls. STp-primed DC induced an immunoregulatory cytokine profile and skin-homing profile on stimulated T-cells. Our data suggest that some of the molecular dialogue between intestinal bacteria and DCs may be mediated by immunomodulatory peptides, encoded in larger extracellular proteins, secreted by commensal bacteria. These peptides may be used for the development of nutraceutical products for patients with IBD. In addition, this kind of peptides seem to be absent in the gut of inflammatory bowel disease patients, suggesting a potential role as biomarker of gut homeostasis. © 2012 Bernardo et al.


Guglielmetti S.,University of Milan | Mayo B.,Institute Productos Lacteos Of Asturias | Alvarez-Martin P.,Nestlé
Beneficial Microbes | Year: 2013

Until recently, proper development of molecular studies in Bifidobacterium species has been hampered by growth difficulties, because of their exigent nutritive requirements, oxygen sensitivity and lack of efficient genetic tools. These studies, however, are critical to uncover the cross-talk between bifidobacteria and their hosts' cells and to prove unequivocally the supposed beneficial effects provided through the endogenous bifidobacterial populations or after ingestion as probiotics. The genome sequencing projects of different bifidobacterial strains have provided a wealth of genetic data that will be of much help in deciphering the molecular basis of the physiological properties of bifidobacteria. To this end, the purposeful development of stable cloning and expression vectors based on robust replicons - either from temperate phages or resident plasmids - is still needed. This review addresses the current knowledge on the mobile genetic elements of bifidobacteria (prophages, plasmids and transposons) and summarises the different types of vectors already available, together with the transformation procedures for introducing DNA into the cells. It also covers recent molecular studies performed with such vectors and incipient results on the genetic modification of these organisms, establishing the basis that would allow the use of bifidobacteria for future biotechnological applications. © 2013 Wageningen Academic Publishers.


Rodriguez-Rubio L.,Institute Productos Lacteos Of Asturias | Martinez B.,Institute Productos Lacteos Of Asturias | Donovan D.M.,U.S. Department of Agriculture | Rodriguez A.,Institute Productos Lacteos Of Asturias | Garcia P.,Institute Productos Lacteos Of Asturias
Critical Reviews in Microbiology | Year: 2013

Virion-associated peptidoglycan hydrolases (VAPGH) are phage-encoded lytic enzymes that locally degrade the peptidoglycan (PG) of the bacterial cell wall during infection. In contrast to endolysins, PGHs that mediate lysis of the host bacteria at the end of the lytic cycle to release of phage progeny, the action of VAPGHs generates a small hole through which the phage tail tube crosses the cell envelope to eject the phage genetic material at the beginning to the infection cycle. The antimicrobial activity of VAPGHs was first discovered through the observation of the phenomenon of 'lysis from without', in which the disruption of the bacterial cell wall occurs prior to phage production and is caused by a high number of phages adsorbed onto the cell surface. Based on a unique combination of properties of VAPGHs such as high specificity, remarkable thermostability, and a modular organization, these proteins are potential candidates as new antibacterial agents, e.g. against antibiotic-resistant bacteria in human therapy and veterinary as well as biopreservatives in food safety, and as biocontrol agents of harmful bacteria in agriculture. This review provides an overview of the different VAPGHs discovered to date and their potential as novel antimicrobials. © 2013 Informa Healthcare USA, Inc.


Cuervo A.,University of Oviedo | Salazar N.,Institute Productos Lacteos Of Asturias | Ruas-Madiedo P.,Institute Productos Lacteos Of Asturias | Gueimonde M.,Institute Productos Lacteos Of Asturias | Gonzalez S.,University of Oviedo
Nutrition Research | Year: 2013

It has recently been suggested that fiber exerts a considerable effect on microbiota composition and on fecal short-chain fatty acid (SCFA) production, the concentration of which in the colon is important for immune regulation and for maintaining gut and overall health. To test the hypothesis that the fiber consumed in a regular diet affects fecal SCFA concentrations in the elderly, the authors investigated the association between different types of fiber intake and fecal SCFA concentrations in 32 institutionalized elderly subjects aged between 76 and 95 years. Food intake was recorded by means of a validated food frequency questionnaire. Total, soluble (pectin and hemicellulose) and insoluble (pectin, hemicellulose, Klason lignin, and cellulose) fiber was determined using Marlett Food Composition Tables. Analysis of acetic, propionic, and butyric acid concentrations was performed using gas chromatography-mass spectrometry. Potato intake was directly associated with SCFA concentrations and apple intake with propionate concentration. Of the fibers, cellulose showed an independent association with acetate and butyrate concentrations, and insoluble pectin explained a part of the variation in propionate. In conclusion, our results provide further evidence regarding the relation between diet and SCFA concentration in the elderly. The identification of an association between the regular intake of foods such as potatoes and the production of SCFAs provides an opportunity to improve public health. © 2013 Elsevier Inc.


Linares D.M.,Institute Productos Lacteos Of Asturias | Del Rio B.,Institute Productos Lacteos Of Asturias | Ladero V.,Institute Productos Lacteos Of Asturias | Martinez N.,Institute Productos Lacteos Of Asturias | And 3 more authors.
Frontiers in Microbiology | Year: 2012

Fermented foods are among the food products more often complained of having caused episodes of biogenic amines (BA) poisoning. Concerning milk-based fermented foods, cheese is the main product likely to contain potentially harmful levels of BA, specially tyramine, histamine, and putrescine. Prompted by the increasing awareness of the risks related to dietary uptake of high biogenic amine loads, in this review we report all those elaboration and processing technological aspects affecting BA biosynthesis and accumulation in dairy foods. Improved knowledge of the factors involved in the synthesis and accumulation of BA should lead to a reduction in their incidence in milk products. Synthesis of BA is possible only when three conditions converge: (i) availability of the substrate amino acids; (ii) presence of microorganisms with the appropriate catabolic pathway activated; and (iii) environmental conditions favorable to the decarboxylation activity.These conditions depend on several factors such as milk treatment (pasteurization), use of starter cultures, NaCl concentration, time, and temperature of ripening and preservation, pH, temperature, or post-ripening technological processes, which will be discussed in this chapter. © 2012 Linares, del Río, Ladero, Martínez, Fernández, Martín and Álvarez.


Margolles A.,Institute Productos Lacteos Of Asturias | Sanchez B.,Institute Productos Lacteos Of Asturias
Applied and Environmental Microbiology | Year: 2012

We have characterized a new strain, Bifidobacterium animalis subsp. lactis CECT 7953, obtained by random UV mutagenesis, which produces less acetic acid than the wild type (CECT 7954) in three different experimental settings: De Man-Rogosa-Sharpe broth without sodium acetate, resting cells, and skim milk. Genome sequencing revealed a single Phe-Ser substitution in the acetate kinase gene product that seems to be responsible for the strain's reduced acid production. Accordingly, acetate kinase specific activity was lower in the low acetate producer. Strain CECT 7953 produced less acetate, less ethanol, and more yoghourt-related volatile compounds in skim milk than the wild type did. Thus, CECT 7953 shows promising potential for the development of dairy products fermented exclusively by a bifidobacterial strain. © 2012, American Society for Microbiology.


Sanchez B.,Institute Productos Lacteos Of Asturias | Gonzalez-Tejedo C.,Institute Productos Lacteos Of Asturias | Ruas-Madiedo P.,Institute Productos Lacteos Of Asturias | Urdaci M.C.,University of Bordeaux 1 | Margolles A.,Institute Productos Lacteos Of Asturias
Applied and Environmental Microbiology | Year: 2011

In the present work, we describe the adhesion capabilities of a recombinant Lactococcus lactis strain producing an extracellular protein from Lactobacillus plantarum. Our results show that this protein may offer the bacterium a mechanism to bind to N-acetylglucosamine-containing polymers, such as human mucins, present in different environments. Copyright © 2011, American Society for Microbiology. All Rights Reserved.


Sanchez B.,Institute Productos Lacteos Of Asturias | Hevia A.,Institute Productos Lacteos Of Asturias | Gonzalez S.,University of Oviedo | Margolles A.,Institute Productos Lacteos Of Asturias
Frontiers in Immunology | Year: 2015

Autoimmune diseases, such as systemic lupus erythematosus (SLE), are caused by a complex interaction of environmental-, genetic-, and sex-related factors. Although SLE has traditionally been considered independent from the microbiota, recent work published during the last 5 years suggests a strong connection between SLE and the composition of our gut commensals as one of the main environmental factors linked to this disease. Preliminary data have evidenced that (i) interaction of certain microbial-derived molecules with specific cell receptors and (ii) the influence of certain commensal microorganisms over specific immune cell subsets plays an important role in the pathogenesis of SLE and SLE-like diseases. In addition, epigenetic changes driven by certain microbial groups have been recently proposed as an additional link between gut microbiota and SLE. As immune responses elicited against commensal bacteria are deeply dependent on the composition of the latter, and as microbial populations can be modified by dietary interventions, identifying the precise gut microorganisms responsible for worsening the SLE symptoms is of crucial importance for this and other SLE-related diseases, including antiphospholipid syndrome or lupus nephritis. In this minireview, the current knowledge on the relationships between microbes and SLE and SLE-related diseases is compiled and discussed. © 2015 Sánchez, Hevia, González and Margolles.


Guinda A.,CSIC - Instituto de la Grasa | Rada M.,CSIC - Instituto de la Grasa | Delgado T.,Institute Productos Lacteos Of Asturias | Gutierrez-Adanez P.,CSIC - Instituto de la Grasa | Castellano J.M.,CSIC - Instituto de la Grasa
Journal of Agricultural and Food Chemistry | Year: 2010

This work establishes a new procedure for the extraction and analysis of pentacyclic triterpenes, with which fruits and leaves from three Spanish olive cultivars ("Picual", "Hojiblanca", and "Arbequina" ) has been studied. The leaf contains important amounts of oleanolic acid (3.0-3.5% DW), followed by significant concentrations of maslinic acid and minor levels of ursolic acid, erythrodiol, and uvaol. The abundance and profile of triterpenoids change during the leaf ontogeny. In the fruit, triterpenes are exclusively located in the epicarp at concentrations 30-fold lower than that in the leaf. Maslinic acid is the main triterpenoid, only accompanied of oleanolic acid. Along the ripening the levels of these triterpenes decreased. All the analyzed leaves and fruits come from the same agricultural estate, with identical climate and culturing conditions. For this reason, the found differences could majorly be attributable to the genetic factors of the olive cultivars. © 2010 American Chemical Society.


Alvarez M.A.,Institute Productos Lacteos Of Asturias | Moreno-Arribas M.V.,Institute Investigacion En Ciencias Of La Alimentacion Cial
Trends in Food Science and Technology | Year: 2014

Biogenic amines (BA) are low-molecular-weight nitrogenous organic bases, which can accumulate in high concentration in food due to microbial activity and cause toxic effects in consumers. In some fermented foods it is difficult to prevent the accumulation of BA since the microbiological/chemical/physical conditions of the fermentation can not be easily modified. An alternative in such cases is the use of food microorganisms that are able to degrade BA once they have been synthesized in the food matrix. In this review, we examine the microorganisms that have demonstrated the ability to degrade BA and their technological relevance in fermented foods. © 2014 .

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