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En los ultimos años han aumentado las evidencias sobre la relación existente entre la microbiota intestinal y la salud. No se conoce con certeza en qué consiste esta microbiota saludable pero se sabe que un desbalance de la misma está relacionado con ciertas enfermedades. Esto, junto con el aumento de evidencias científicas sobre su eficacia, ha incrementado el uso de probióticos para intentar equilibrar la microbiota. Las bacterias probióticas de mayor uso pertenecen a los géneros Lactobacillus y Bifidobacterium. Entre las bifidobacterias destaca la utilización comercial de la especie Bifidobacterium animalis subsp. lactis. Resulta de gran importancia profundizar en el conocimiento del efecto de la interacción hospedador ¿ probiótico para lo que se pueden utilizar modelos de líneas celulares intestinales. En el caso del probiótico es recomendable trabajar con aquella fracción bacteriana que ha estado intimamente unida a la célula eucariota, que será la que, en teoría, ejerza el mayor efecto. El porcentaje de adhesión a la célula eucariota así como la facilidad para separar la población adherida, tanto de la bacteria no adherida como de la línea celular, son claves para abordar estudios transcriptomicos. Por ello, el objetivo del presente trabajo fue optimizar un protocolo de extracción del RNA de la población de cepas de B. animalis subsp. lactis, productoras de distintos exopolisacáridos (EPS), adherida a la línea celular de colon HT29. Este hecho nos permitió estudiar la expresión génica diferencial entre dos cepas isogénicas que únicamente difieren en el tipo de EPS que producen, los cuales inducen respuestas inmunes diferentes

Our group has recently proved the existence of a gut microbial dysbiosis in patients with systemic lupus erythematosus (SLE), resulting in differences in the ratio Firmicutes/Bacteroidetes, and supporting previous evidence involving intestinal bacteria in the initiation and amplification of inflammatory processes and autoimmune diseases. While several studies have addressed the use of dietary fibres to modify intestinal microbial populations, information about other highly correlated components, such as polyphenols, is scarce. The aim of this work was the identification of dietary components able to influence this altered microbiota in 20 women suffering from SLE and 20 age-matched controls. Food intake was recorded by means of a food frequency questionnaire. Energy was calculated from CESNID food composition tables and Phenol-Explorer was used for polyphenol intake. Results showed positive associations between flavone intake and Blautia, flavanones and Lactobacillus and dihydrochalcones and Bifidobacterium in the SLE group. Regarding the controls, dihydroflavonols were directly associated with Faecalibacterium, whereas flavonol intake was inversely associated with Bifidobacterium. From the food sources of these polyphenols related to microbiota, orange intake was directly associated with Lactobacillus and apple with Bifidobacterium in SLE, whilst red wine was the best contributor to Faecalibacterum variation. The association between common foods and particular microbial genera, reported to be decreased in SLE, could be of great importance for these patients

[ES] Dispositivo de recogida y traslado de muestras en anaerobiosis, que comprende un recipiente (1) con una abertura (2), y un cierre (4) para cubrir dicha abertura (2), en el que el cierre (4) incorpora un tapón activador (6) manualmente accionable que libera un elemento activador contenido en una bolsa (8) para comenzar una cadena de reacciones determinadas por un material reactivo (13) capaz de crear una atmósfera anaerobia en el interior del recipiente (1). El dispositivo está preferentemente concebido para el caso en que dichas muestras sean heces, de origen humano o animal, con el objeto de conservar viable la microbiota intestinal y poder proceder a su posterior revivificación en laboratorio., [EN] A device for collecting and transferring samples in anaerobiosis, comprising a vessel (1) with an opening (2), and a closure (4) for covering the opening (2), in which the closure (4) incorporates a manually operated activator plug (6) that releases an activator element contained in a bag (8) to start a chain of reactions determined by a reagent material (13) capable of creating an anaerobic atmosphere inside the vessel (1). The device is preferably designed for the case in which said samples are stool, of human or animal origin, with the aim of preserving the viability of the gut microbiota and being able to proceed with their later revival in the laboratory.

[EN] A device for collecting and transferring samples in anaerobiosis, comprising a vessel (1) with an opening (2), and a closure (4) for covering the opening (2), in which the closure (4) incorporates a manually operated activator plug (6) that releases an activator element contained in a bag (8) to start a chain of reactions determined by a reagent material (13) capable of creating an anaerobic atmosphere inside the vessel (1). The device is preferably designed for the case in which said samples are stool, of human or animal origin, with the aim of preserving the viability of the gut microbiota and being able to proceed with their later revival in the laboratory., [ES] Dispositivo de recogida y traslado de muestras en anaerobiosis, que comprende un recipiente (1) con una abertura (2), y un cierre (4) para cubrir dicha abertura (2), en el que el cierre (4) incorpora un tapón activador (6) manualmente accionable que libera un elemento activador contenido en una bolsa (8) para comenzar una cadena de reacciones determinadas por un material reactivo (13) capaz de crear una atmósfera anaerobia en el interior del recipiente (1). El dispositivo está preferentemente concebido para el caso en que dichas muestras sean heces, de origen humano o animal, con el objeto de conservar viable la microbiota intestinal y poder proceder a su posterior revivificación en laboratorio.

Metabolic impairments are a frequent hallmark of systemic lupus erythematosus (SLE). Increased serum levels of free fatty acids (FFA) are commonly found in these patients, although the underlying causes remain elusive. Recently, it has been suggested that factors other than inflammation or clinical features may be involved. The gut microbiota is known to influence the host metabolism, the production of short-chain fatty acids (SCFA) playing a potential role. Taking into account that lupus patients exhibit an intestinal dysbiosis, we wondered whether altered FFA levels may be associated with the intestinal microbial composition in lupus patients. To this aim, total and specific serum FFA levels, fecal SCFA levels, and gut microbiota composition were determined in 21 SLE patients and 25 healthy individuals. The Firmicutes to Bacteroidetes (F/B) ratio was strongly associated with serum FFA levels in healthy controls (HC), even after controlling for confounders. However, this association was not found in lupus patients, where a decreased F/B ratio and increased FFA serum levels were noted. An altered production of SCFA was related to the intestinal dysbiosis in lupus, while SCFA levels paralleled those of serum FFA in HC. Although a different serum FFA profile was not found in SLE, specific FFA showed distinct patterns on a principal component analysis. Immunomodulatory omega-3 FFA were positively correlated to the F/B ratio in HC, but not in SLE. Furthermore, divergent associations were observed for pro- and anti-inflammatory FFA with endothelial activation biomarkers in lupus patients. Overall, these findings support a link between the gut microbial ecology and the host metabolism in the pathological framework of SLE. A potential link between intestinal dysbiosis and surrogate markers of endothelial activation in lupus patients is supported, FFA species having a pivotal role.

Accumulated evidence suggests a relationship between specific allergic processes, such as atopic eczema in children, and an aberrant fecal microbiota. However, little is known about the complete microbiota profile of adult individuals suffering from asthma. We determined the fecal microbiota in 21 adult patients suffering allergic asthma (age 39.43 ± 10.98 years old) and compare it with the fecal microbiota of 22 healthy controls (age 39.29 ± 9.21 years old) using culture independent techniques. An Ion-Torrent 16S rRNA gene-based amplification and sequencing protocol was used to determine the fecal microbiota profile of the individuals. Sequence microbiota analysis showed that the microbial alpha-diversity was not significantly different between healthy and allergic individuals and no clear clustering of the samples was obtained using an unsupervised principal component analysis. However, the analysis of specific bacterial groups allowed us to detect significantly lower levels of bifidobacteria in patients with long-term asthma. Also, in allergic individuals the Bifidobacterium adolescentis species prevailed within the bifidobacterial population. The reduction in the levels on bifidobacteria in patients with long-term asthma suggests a new target in allergy research and opens possibilities for the therapeutic modulation of the gut microbiota in this group of patients.

A better understanding of the interactions among intestinal microbes is needed to decipher the complex cross talk that takes place within the human gut. Bacteroides and Bifidobacterium genera are among the most relevant intestinal bacteria, and it has been previously reported that coculturing of these 2 microorganisms affects their survival. Therefore, coculturing of Bifidobacterium longum NB667 and Bacteroides fragilis DSMZ2151 was performed with the aim of unravelling the mechanisms involved in their interaction. To this end, we applied proteomic (2D-DIGE) analyses, and by chromatographic techniques we quantified the bacterial metabolites produced during coincubation. Coculture stimulated the growth of B. longum, retarding that of B. fragilis, with concomitant changes in the production of some proteins and metabolites of both bacteria. The combined culture promoted upregulation of the bifidobacterial pyruvate kinase and downregulation of the Bacteroides phosphoenolpyruvate carboxykinase - 2 enzymes involved in the catabolism of carbohydrates. Moreover, B. fragilis FKBP-type peptidyl-prolyl cis-trans isomerase, a protein with chaperone-like activity, was found to be overproduced in coculture, suggesting the induction of a stress response in this microorganism. This study provides mechanistic data to deepen our understanding of the interaction between Bacteroides and Bifidobacterium intestinal populations. Copyright NRC Research Press

Bifidobacteria are commensal microoganisms found in the gastrointestinal tract. Several strains have been attributed beneficial traits at local and systemic levels, through pathogen exclusion or immune modulation, among other benefits. This has promoted a growing industrial and scientific interest in bifidobacteria as probiotic supplements. However, the molecular mechanisms mediating this cross-talk with the human host remain unknown. High-throughput technologies, from functional genomics to transcriptomics, proteomics, and interactomics coupled to the development of both in vitro and in vivo models to study the dynamics of the intestinal microbiota and their effects on host cells, have eased the identification of key molecules in these interactions. Numerous secreted or surface-associated proteins or peptides have been identified as potential mediators of bifidobacteria-host interactions and molecular cross-talk, directly participating in sensing environmental factors, promoting intestinal colonization, or mediating a dialogue with mucosa-associated immune cells. On the other hand, bifidobacteria induce the production of proteins in the intestine, by epithelial or immune cells, and other gut bacteria, which are key elements in orchestrating interactions among bifidobacteria, gut microbiota, and host cells. This review aims to give a comprehensive overview on proteinaceous molecules described and characterized to date, as mediators of the dynamic interplay between bifidobacteria and the human host, providing a framework to identify knowledge gaps and future research needs.

Purpose of review Recent discoveries relay commensal gut microbiota as a relevant factor in the maintenance of intestinal homeostasis. Recent findings Alterations in the composition of the intestinal microbiota have been reported in patients with systemic lupus erythematosus and many other inflammatory and autoimmune conditions. However, the mechanisms by which the intestinal microbiota can influence systemic immunity in these situations remain to be elucidated. The inappropriate immune responses of patients with systemic lupus erythematosus could originate a breakdown of tolerance towards the microbiota, leading to the expansion and/or contraction of specific bacterial groups that may culminate in a dysbiotic state. Conversely, an altered composition of the intestinal microbiome in genetically predisposed individuals could influence systemic immunity by several mechanisms, leading to a breakdown of tolerance to self-antigens. Moreover, humoral immune responses can be affected by specific bacterial groups in these individuals. Summary Recent findings support an important role for the crosstalk between bacteria and immune cells to maintain an intestinal homeostasis crucial to sustain tolerance toward self-antigens and intestinal microbiota.

Bifidobacteria are gut commensal microorganisms belonging to the Actinobacteria group. Some specific strains of Bifidobacterium animalis subsp. lactis are used in functional foods as they are able to exert health-promoting effects in the human host. Due to the limited genetic variability within this subspecies, it is sometimes difficult for a manufacturer to properly track its strain once included in dairy products or functional foods. In this paper, we present a peptidome-based analysis in which the proteomes of a set of B. animalis subsp. lactis strains were digested in silico with human gut endopeptidases. The molecular masses were compared along all the strains to detect strain-specific peptides. These peptides may be interesting towards the development of methodologies for strain identification in the final product.

Microorganisms of the genus Bifidobacterium are inhabitants of diverse niches including the digestive tract of humans and animals. The species Bifidobacterium adolescentis, Bifidobacterium animalis, Bifidobacterium bifidum, Bifidobacterium breve and Bifidobacterium longum have qualified presumption of safety status granted by EFSA and several strains are considered probiotic, and are being included in functional dairy fermented products. In the present work we carried out a preliminary exploration of general metabolic characteristics and organic acid production profiles of a reduced number of strains selected from these and other species of the genus Bifidobacterium. The use of resting cells allowed obtaining metabolic fingerprints without interference of metabolites accumulated during growth in culture media. Acetic acid was the most abundant organic acid formed per mol of glucose consumed (from 1.07±0.03 to 1.71±0.22 mol) followed by lactic acid (from 0.34±0.06 to 0.90±0.12 mol), with moderate differences in production among strains; pyruvic, succinic and formic acids were also produced at considerably lower proportions, with variability among strains. The acetic to lactic acid ratio showed lower values in stationary phase as regard to the exponential phase for most, but not all, the microorganisms; this was due to a decrease in acetic acid molar proportions together with increases of lactic acid proportions in stationary phase. A linear discriminant analysis allowed to cluster strains into species with 51-100% probability, evidencing different metabolic profiles, according to the relative production of organic acids from glucose by resting cells, of microorganisms collected at the exponential phase of growth. Looking for a single metabolic marker that could adequately discriminate metabolic groups, we found that groups established by the acetic to lactic acid ratio fit well with differences previously evidenced by the discriminant analysis. The proper establishme

Chemoprevention is the use of natural and/or synthetic substances to block, reverse, or retard the process of carcinogenesis. In this field, the use of antitumor peptides is of interest as, (i) these molecules are small in size, (ii) they show good cell diffusion and permeability, (iii) they affect one or more specific molecular pathways involved in carcinogenesis, and (iv) they are not usually genotoxic. We have checked the Web of Science Database (23/11/2015) in order to collect papers reporting on bioactive peptide (1691 registers), which was further filtered searching terms such as >antiproliferative,> >antitumoral,> or >apoptosis> among others. Works reporting the amino acid sequence of an antiproliferative peptide were kept (60 registers), and this was complemented with the peptides included in CancerPPD, an extensive resource for antiproliferative peptides and proteins. Peptides were grouped according to one of the following mechanism of action: inhibition of cell migration, inhibition of tumor angiogenesis, antioxidative mechanisms, inhibition of gene transcription/cell proliferation, induction of apoptosis, disorganization of tubulin structure, cytotoxicity, or unknown mechanisms. The main mechanisms of action of those antiproliferative peptides with known amino acid sequences are presented and finally, their potential clinical usefulness and future challenges on their application is discussed.

[Background] The microbial colonization of the neonatal gut provides a critical stimulus for normal maturation and development. This process of early microbiota establishment, known to be affected by several factors, constitutes an important determinant for later health., [Methods] We studied the establishment of the microbiota in preterm and full-term infants and the impact of perinatal antibiotics upon this process in premature babies. To this end, 16S rRNA gene sequence-based microbiota assessment was performed at phylum level and functional inference analyses were conducted. Moreover, the levels of the main intestinal microbial metabolites, the short-chain fatty acids (SCFA) acetate, propionate and butyrate, were measured by Gas-Chromatography Flame ionization/Mass spectrometry detection., [Results] Prematurity affects microbiota composition at phylum level, leading to increases of Proteobacteria and reduction of other intestinal microorganisms. Perinatal antibiotic use further affected the microbiota of the preterm infant. These changes involved a concomitant alteration in the levels of intestinal SCFA. Moreover, functional inference analyses allowed for identifying metabolic pathways potentially affected by prematurity and perinatal antibiotics use., [Conclusion] A deficiency or delay in the establishment of normal microbiota function seems to be present in preterm infants. Perinatal antibiotic use, such as intrapartum prophylaxis, affected the early life microbiota establishment in preterm newborns, which may have consequences for later health.

Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. Many strains exert their beneficial effects after transiently colonizing the human gut, where they interact with the rest of the intestinal microorganisms and with the host mucosa. Indeed the human gut harbours a huge number of microorganisms also known as gut microbiota. Imbalances in the relative abundances of the individual components of the gut microbiota may determine the health status of the host and alterations in specific groups have been related to different diseases and metabolic disorders. Proteomics provide a set of high-throughput methodologies for protein identification that are extremely useful for studying probiotic functionality and helping in the assessment of specific health-promoting activities, such as their immunomodulatory activity, the intestinal colonization processes, and the crosstalk mechanisms with the host. Furthermore, proteomics have been used to identify markers of technological performance and stress adaptation, which helps to predict traits such as behaviour into food matrices and ability to survive passage through the gastrointestinal tract. The aim of this review is to compile studies in which proteomics have been used to assess probiotic functionality and to identify molecular players supporting their mechanisms of action. Significance Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. Molecular basis underlying the functional properties of probiotic bacteria responsible for the health promoting effects have been in the background for many years. Breakthrough of omics technologies in the probiotic and microbiota fields has had a very relevant impact in the elucidation of probiotic mechanisms and in the procedures to select these microorganisms, based on solid scientific evidence. It is unquestionable that, in the near future, the evolution of proteomi

Our group has recently shown the existence of a gut microbial dysbiosis in systemic lupus erythematosus (SLE), supporting previous evidence involving intestinal bacteria in the initiation and amplification of autoimmune diseases. While several studies have addressed the use of dietary fibres to modify intestinal microbiota, information about other correlated components, such as polyphenols, is scarce. The aim of this work was to identify dietary components able to influence this altered microbiota in 20 SLE women and 20 age-matched controls. Food intake was recorded by means of a food frequency questionnaire. The intake of fibres was calculated from Marlett tables, and Phenol-Explorer was used for polyphenol consumption. Results showed positive associations between flavone intake and Blautia, flavanones and Lactobacillus, and dihydrochalcones and Bifidobacterium in the SLE group. Regarding the controls, dihydroflavonols were directly associated with Faecalibacterium, whereas flavonol intake was inversely associated with Bifidobacterium. From the food sources of these polyphenols related to microbiota, orange intake was directly associated with Lactobacillus and apple with Bifidobacterium in SLE, whilst red wine was the best contributor to Faecalibacterium variation. The association between common foods and particular microbial genera, reported to be decreased in SLE, could be of great importance for these patients.

The use of beneficial microorganisms, the so-called probiotics, to improve human health is gaining popularity. However, not all of the probiotic strains trigger the same responses and they differ in their interaction with the host. In spite of the limited knowledge on mechanisms of action some of the probiotic effects seem to be exerted through maintenance of the gastrointestinal barrier function and modulation of the immune system. In the present work, we have addressed in vitro the response of the intestinal epithelial cell line HT29 to the strain Bifidobacterium breve IPLA20004. In the array of 84 genes involved in inflammation tested, the expression of 12 was modified by the bifidobacteria. The genes of chemokine CXCL6, the chemokine receptor CCR7, and, specially, the complement component C3 were upregulated. Indeed, HT29 cells cocultivated with B. breve produced significantly higher levels of protein C3a. The proteome of HT29 cells showed increased levels of cytokeratin-8 in the presence of B. breve. Altogether, it seems that B. breve IPLA20004 could favor the recruitment of innate immune cells to the mucosa reinforcing, as well as the physical barrier of the intestinal epithelium. © 2015 Borja Sánchez et al.

Bifidobacteria are common and frequently dominant members of the gut microbiota of many animals, including mammals and insects. Carbohydrates are considered key carbon sources for the gut microbiota, imposing strong selective pressure on the complex microbial consortium of the gut. Despite its importance, the genetic traits that facilitate carbohydrate utilization by gut microbiota members are still poorly characterized. Here, genome analyses of 47 representative Bifidobacterium (sub)species revealed the genes predicted to be required for the degradation and internalization of a wide range of carbohydrates, outnumbering those found in many other gut microbiota members. The glycan-degrading abilities of bifidobacteria are believed to reflect available carbon sources in the mammalian gut. Furthermore, transcriptome profiling of bifidobacterial genomes supported the involvement of various chromosomal loci in glycan metabolism. The widespread occurrence of bifidobacterial saccharolytic features is in line with metagenomic and metatranscriptomic datasets obtained from human adult/infant faecal samples, thereby supporting the notion that bifidobacteria expand the human glycobiome. This study also underscores the hypothesis of saccharidic resource sharing among bifidobacteria through species-specific metabolic specialization and cross feeding, thereby forging trophic relationships between members of the gut microbiota.

The dietary modulation of gut microbiota, suggested to be involved in allergy processes, has recently attracted much interest. While several studies have addressed the use of fibres to modify intestinal microbial populations, information about other components, such as phenolic compounds, is scarce. The aim of this work was to identify the dietary components able to influence the microbiota in 23 subjects suffering from rhinitis and allergic asthma, and 22 age- and sex-matched controls. The food intake was recorded by means of an annual food frequency questionnaire. Dietary fibre tables were obtained from Marlett et al., and the Phenol-Explorer database was used to assess the phenolic compound intake. The quantification of microbial groups was performed using an Ion Torrent 16S rRNA gene-based analysis. The results showed a direct association between the intake of red wine, a source of stilbenes, and the relative abundance of Bacteroides, and between the intake of coffee, rich in phenolic acids, and the abundance of Clostridium, Lactococcus and Lactobacillus genera. Despite epidemiological analyses not establishing causality, these results support the association between polyphenol-rich beverages and faecal microbiota in allergic patients.

Bifidobacteria are bacterial gut commensals of mammals, birds and social insects that are perceived to influence the metabolism/physiology of their host. In this context, members of the Bifidobacterium bifidum species are believed to significantly contribute to the overall microbiota of the human gut at infant stage. However, the molecular reasons for their adaptation to this environment are poorly understood. In this study, we analysed the pan-genome of B.bifidum species by decoding genomes of 15 B.bifidum strains, which highlighted the existence of a conserved gene uniquely present in this bifidobacterial taxon, underscoring a nutrient acquisition strategy that targets host-derived glycans, such as those present in mucin. Growth experiments and corresponding transcriptomic analyses confirmed the in silico data and supported these intriguing and unique host glycan-specific saccharolytic features. The ubiquity of the genetic features of B.bifidum for the breakdown of host glycans was confirmed by interrogating metagenomic datasets, thereby supporting the notion that metabolic access to host-derived glycans is a potent evolutionary force that has shaped B.bifidum genomes and consequently the ecology of the infant intestinal microbiota. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

The commensal microbiota modulates immunological and metabolic aspects of the intestinal mucosa contributing to development of human gut diseases including inflammatory bowel disease. The host/microbiota interaction often referred to as a crosstalk, mainly focuses on the effect of the microbiota on the host neglecting effects that the host could elicit on the commensals. Colonic microenvironments from three human healthy controls (obtained from the proximal and distal colon, both in resting conditions and after immune - IL-15-and microbiota - LPS-in vitro challenges) were used to condition a stable fecal population. Subsequent 16S rRNA gene-based analyses were performed to study the effect induced by the host on the microbiota composition and function. Non-supervised principal component analysis (PCA) showed that all microbiotas, which had been conditioned with colonic microenvironments clustered together in terms of relative microbial composition, suggesting that soluble factors were modulating a stable fecal population independently from the treatment or the origin. Our findings confirmed that the host intestinal microenvironment has the capacity to modulate the gut microbiota composition via yet unidentified soluble factors. These findings indicate that an appropriate understanding of the factors of the host mucosal microenvironment affecting microbiota composition and function could improve therapeutic manipulation of the microbiota composition.

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.

The vaginal microbiota of healthy, fertile women is dominated by lactobacilli. As a defence mechanism, these bacteria produce H2O2 to discourage colonization of the vagina by undesirable micro-organisms. In particular, Lactobacillus jensenii CECT 4306 is a strong producer of H2O2 and has been found to protect itself from the bactericidal effects of this compound through the activity of extracellular peroxidases. However, this peroxidase activity is dependent on the presence of Fe3+, which is found in elevated concentrations in the vaginal mucosa as a consequence of the menstrual discharge. The aim of the present work was to evaluate whether Fe3+ is able to modulate other potential probiotic properties of strain 4306. We found that Fe3+ enhances the adhesion of L. jensenii CECT 4306 to mucin and to HT-29 and HT-29 MTX cells, and, in addition, improves the anti-inflammatory profile, as judged by an increase in the ratio of IL- 10/IL-12p70 that were secreted by macrophages. A comparison of total, secreted and surface proteins produced in the presence and absence of Fe3+ revealed significant differences in the concentration of the moonlighting protein glyceraldehyde-3-phosphate dehydrogenase (GAPDH). In conclusion, Fe3+ seems to improve the probiotic characteristics of L. jensenii CECT 4306, and future research of the interactions of this strain with its vaginal environment may reveal further information about different aspects of its probiotic potential. © 2015 The Authors.

Multiple factors have been shown to alter intestinal microbial diversity. It remains to be seen, however, how multiple collective pressures impact the activity in the gut environment and which, if any, is positioned as a dominant driving factor determining the final metabolic outcomes. Here, we describe the results of a metabolome-wide scan of gut microbiota in 18 subjects with systemic lupus erythematosus (SLE) and 17 healthy control subjects and demonstrate a statistically significant difference (p < 0.05) between the two groups. Healthy controls could be categorized (p < 0.05) based on their body mass index (BMI), whereas individuals with SLE could not. We discuss the prevalence of SLE compared with BMI as the dominant factor that regulates gastrointestinal microbial metabolism and provide plausible explanatory causes. Our results uncover novel perspectives with clinical relevance for human biology. In particular, we rank the importance of various pathophysiologies for gut homeostasis.

Bacteroides is among the most abundant microorganism inhabiting the human intestine. They are saccharolytic bacteria able to use dietary or host-derived glycans as energy sources. Some Bacteroides fragilis strains contribute to the maturation of the immune system but it is also an opportunistic pathogen. The intestine is the habitat of most Bifidobacterium species, some of whose strains are considered probiotics. Bifidobacteria can synthesize exopolysaccharides (EPS), which are complex carbohydrates that may be available in the intestinal environment. We studied the metabolism of B. fragilis when an EPS preparation from bifidobacteria was added to the growth medium compared to its behavior with added glucose. 2D-DIGE coupled with the identification by MALDI-TOF/TOF evidenced proteins that were differentially produced when EPS was added. The results were supported by RT qPCR gene expression analysis. The intracellular and extracellular pattern of certain amino acids, the redox balance and the a-glucosidase activity were differently affected in EPS with respect to glucose. These results allowed us to hypothesize that three general main events, namely the activation of amino acids catabolism, enhancement of the transketolase reaction from the pentose-phosphate cycle, and activation of the succinate-propionate pathway, promote a shift of bacterial metabolism rendering more reducing power and optimizing the energetic yield in the form of ATP when Bacteroides grow with added EPS. Our results expand the knowledge about the capacity of B. fragilis for adapting to complex carbohydrates and amino acids present in the intestinal environment. © 2015 Rios-covian, Sanchez, Salazar, Martinez, Redruello, Gueimonde and De los Reyes-Gavilan.

The human gastrointestinal tract is a very complex ecosystem, in which there is a continuous interaction between nutrients, host cells, and microorganisms. The gut microbiota comprises trillions of microbes that have been selected during evolution on the basis of their functionality and capacity to survive in, and adapt to, the intestinal environment. Host bacteria and our immune system constantly sense and react to one another. In this regard, commensal microbes contribute to gut homeostasis, whereas the necessary responses are triggered against enteropathogens. Some representatives of our gut microbiota have beneficial effects on human health. Some of the most important roles of these microbes are to help to maintain the integrity of the mucosal barrier, to provide nutrients such as vitamins, or to protect against pathogens. In addition, the interaction between commensal microbiota and the mucosal immune system is crucial for proper immune function. This process is mainly performed via the pattern recognition receptors of epithelial cells, such as Toll-like or Nod-like receptors, which are able to recognize the molecular effectors that are produced by intestinal microbes. These effectors mediate processes that can ameliorate certain inflammatory gut disorders, discriminate between beneficial and pathogenic bacteria, or increase the number of immune cells or their pattern recognition receptors (PRRs). This review intends to summarize the molecular players produced by probiotic bacteria, notably Lactobacillus and Bifidobacterium strains, but also other very promising potential probiotics, which affect the human immune system. This Document is Protected by copyright and was first published by Frontiers. All rights reserved. it is reproduced with permission.