Evaluation of an O2-Substituted (1–3)-β-D-Glucan, Produced by Pediococcus parvulus 2.6, in ex vivo Models of Crohn’s Disease

Efecte antiinflamatori de la malaltia de Crohn; Immunomodulació; Exopolisacàrids bacteriansEfecto antiinflamatorio de la enfermedad de Crohn; Inmunomodulacion; Exopolisacáridos bacterianosCrohn's disease anti-inflammatory effect; Immunomodulation; Bacterial exopolysaccharides1,3-β-glucans are extracellular polysaccharides synthesized by microorganisms and plants, with therapeutic potential. Among them, the O2-substituted-(1–3)-β-D-glucan, synthesized by some lactic acid bacteria (LAB), has a prebiotic effect on probiotic strains, an immunomodulatory effect on monocyte-derived macrophages, and potentiates the ability of the producer strain to adhere to Caco-2 cells differentiated to enterocytes. In this work, the O2-substituted-(1–3)-β-D-glucan polymers produced by GTF glycoyltransferase in the natural host Pediococcus parvulus 2.6 and in the recombinant strain Lactococcus lactis NZ9000[pNGTF] were tested. Their immunomodulatory activity was investigated in an ex vivo model using human biopsies from patients affected by Crohn’s disease (CD). Both polymers had an anti-inflammatory effect including, a reduction of Interleukine 8 both at the level of its gene expression and its secreted levels. The overall data indicate that the O2-substituted-(1–3)-β-D-glucan have a potential role in ameliorating inflammation via the gut immune system cell modulation.This work was supported by the Spanish Ministry of Science, Innovation, and Universities (grant RTI2018-097114-B-I00), by the Fondo de Investigación Sanitaria, grant number PI12/00263, and by CIBERehd

Mutual modulation of gut microbiota and the immune system in type 1 diabetes models

Immunological disorders; Metabolic disorders; Molecular biologyTrastorns immunològics; Trastorns metabòlics; Biologia molecularTrastornos inmunológicos; Trastornos metabólicos; Biología MolecularThe transgenic 116C-NOD mouse strain exhibits a prevalent Th17 phenotype, and reduced type 1 diabetes (T1D) compared to non-obese diabetic (NOD) mice. A cohousing experiment between both models revealed lower T1D incidence in NOD mice cohoused with 116C-NOD, associated with gut microbiota changes, reduced intestinal permeability, shifts in T and B cell subsets, and a transition from Th1 to Th17 responses. Distinct gut bacterial signatures were linked to T1D in each group. Using a RAG-2−/− genetic background, we found that T cell alterations promoted segmented filamentous bacteria proliferation in young NOD and 116C-NOD, as well as in immunodeficient NOD.RAG-2−/− and 116C-NOD.RAG-2−/− mice across all ages. Bifidobacterium colonization depended on lymphocytes and thrived in a non-diabetogenic environment. Additionally, 116C-NOD B cells in 116C-NOD.RAG-2−/− mice enriched the gut microbiota in Adlercreutzia and reduced intestinal permeability. Collectively, these results indicate reciprocal modulation between gut microbiota and the immune system in rodent T1D models.This work was supported by the Plan Nacional de I + D + i of the Spanish Ministry of Science and Innovation (PID2019-109302RB-I00), the DiabetesCERO Foundation (Becas Impulso Talento Joven 2022), and CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM) that is an initiative from Instituto de Salud Carlos III (Spain). E.R.-M. was supported by predoctoral fellowships from the Generalitat de Catalunya (AGAUR FI-DGR, grant number: 2013FI_B 00585), the Spanish Government (FPU, grant number: FPU13/02045) and the IRBLleida. M.C.-P., B.A., and L.E.-M. were supported by UdL and IRBLleida predoctoral fellowships. F. Y. was supported by a predoctoral fellowship from the Chilean Government (ANID, grant number: 72190278). G.S.-G. was supported by a predoctoral fellowship from VHIR

Activation of immune and defense responses in the intestinal mucosa by outer membrane vesicles of commensal and probiotic Escherichia coli strains

The influence of microbiota in human health is well established. Imbalances in microbiome structure have been linked to several diseases. Modulation of microbiota composition through probiotic therapy is an attempt to harness the beneficial effects of commensal microbiota. Although there is wide knowledge of the responses induced by gut microbiota, the microbial factors that mediate these effects are not fully known. Gram-negative bacteria release outer membrane vesicles (OMVs) as a delivery mechanism of microbial factors, having an important role in intercellular communication. Here we investigated whether OMVs from the probiotic Escherichia coli strain Nissle 1917 or the commensal E. coli strain ECOR12 trigger immune responses in various cellular models: (i) peripheral blood mononuclear cells (PBMCs) as a model of intestinal barrier disruption, (ii) apical stimulation of Caco-2/PMBCs co-culture as a model of intact intestinal mucosa, and (iii) colonic mucosa explants as an ex vivo model. Stimulations with bacterial lysates were also performed for comparison. Whereas OMVs and lysates activated expression and secretion of several cytokines and chemokines in PBMCs, only OMVs induced basolateral secretion and mRNA upregulation of these mediators in the co-culture model. We provide evidence that OMVs are internalized in polarized Caco-2 cells, and that activated epithelial cells elicit a response in the underlying immunocompetent cells. The OMVs effects were corroborated in the ex vivo model. This experimental study shows that OMVs are an effective strategy used by beneficial gut bacteria to communicate with and modulate host responses, activating signaling events through the intestinal epithelial barrier.

Dysbiosis and relapse-related microbiome in inflammatory bowel disease: A shotgun metagenomic approach

© 2021 The Author(s).Crohn’s disease (CD) and ulcerative colitis (UC), the two main forms of inflammatory bowel disease (IBD), affect several million people worldwide. CD and UC are characterized by periods of clinical remission and relapse. Although IBD patients present chronic alterations of the gut microbiome, called dysbiosis, little attention has been devoted to the relapse-related microbiome. To address this gap, we generated shotgun metagenomic data from the stools of two European cohorts—134 Spanish (followed up for one year) and 49 Belgian (followed up for 6 months) subjects—to characterize the microbial taxonomic and metabolic profiles present. To assess the predictive value of microbiome data, we added the taxonomic profiles generated from a previous study of 130 Americans. Our results revealed that CD was more dysbiotic than UC compared to healthy controls (HC) and that strategies for energy extraction and propionate production were different in CD compared to UC and HC. Remarkably, CD and UC relapses were not associated with alpha- or beta-diversity, or with a dysbiotic score. However, CD relapse was linked to alterations at the species and metabolic pathway levels, including those involved in propionate production. The random forest method using taxonomic profiles allowed the prediction of CD vs. non-CD with an AUC = 0.938, UC vs. HC with an AUC = 0.646, and CD relapse vs. remission with an AUC = 0.769. Our study validates previous taxonomic findings, points to different relapse-related growth and defence mechanisms in CD compared to UC and HC and provides biomarkers to discriminate IBD subtypes and predict disease activity.This study was supported by the Instituto de Salud Carlos III /FEDER, a government agency (grant numbers: PI17/00614; PI20/00130), and by the Crohn’s & Colitis Foundation of America (Award ID: 514634)

Anal gas evacuation and colonic microbiota in patients with flatulence : effect of diet

Altres ajuts:This work was supported by the , Fundació La Marató TV3 (MARATV3_072010), the European Community's Seventh Framework Programme (FP7/2007-2013: IHMS, grant agreement HEALTH.2010.2.1.1-2) and a grant from Danone Research (France). Ciberehd is funded by the Instituto de Salud Carlos III.To characterise the influence of diet on abdominal symptoms, anal gas evacuation, intestinal gas distribution and colonic microbiota in patients complaining of flatulence. Patients complaining of flatulence (n=30) and healthy subjects (n=20) were instructed to follow their usual diet for 3 days (basal phase) and to consume a high-flatulogenic diet for another 3 days (challenge phase). During basal phase, patients recorded more abdominal symptoms than healthy subjects in daily questionnaires (5.8±0.3 vs 0.4±0.2 mean discomfort/pain score, respectively; p=<0.0001) and more gas evacuations by an event marker (21.9±2.8 vs 7.4±1.0 daytime evacuations, respectively; p=0.0001), without differences in the volume of gas evacuated after a standard meal (262±22 and 265±25 mL, respectively). On flatulogenic diet, both groups recorded more abdominal symptoms (7.9±0.3 and 2.8±0.4 discomfort/pain, respectively), number of gas evacuations (44.4±5.3 and 21.7±2.9 daytime evacuations, respectively) and had more gas production (656±52 and 673±78 mL, respectively; p<0.05 vs basal diet for all). When challenged with flatulogenic diet, patients' microbiota developed instability in composition, exhibiting variations in the main phyla and reduction of microbial diversity, whereas healthy subjects' microbiota were stable. Taxa from Bacteroides fragilis or Bilophila wadsworthia correlated with number of gas evacuations or volume of gas evacuated, respectively. Patients complaining of flatulence have a poor tolerance of intestinal gas, which is associated with instability of the microbial ecosystem

Reshaping the gut microbiome with bacterial transplantation and antibiotic intake

The intestinal microbiota consists of over 1000 species, which play key roles in gut physiology and homeostasis. Imbalances in the composition of this bacterial community can lead to transient intestinal dysfunctions and chronic disease states. Understanding how to manipulate this ecosystem is thus essential for treating many disorders. In this study, we took advantage of recently developed tools for deep sequencing and phylogenetic clustering to examine the long-term effects of exogenous microbiota transplantation combined with and without an antibiotic pretreatment. In our rat model, deep sequencing revealed an intestinal bacterial diversity exceeding that of the human gut by a factor of two to three. The transplantation produced a marked increase in the microbial diversity of the recipients, which stemmed from both capture of new phylotypes and increase in abundance of others. However, when transplantation was performed after antibiotic intake, the resulting state simply combined the reshaping effects of the individual treatments (including the reduced diversity from antibiotic treatment alone). Therefore, lowering the recipient bacterial load by antibiotic intake prior to transplantation did not increase establishment of the donor phylotypes, although some dominant lineages still transferred successfully. Remarkably, all of these effects were observed after 1 mo of treatment and persisted after 3 mo. Overall, our results indicate that the indigenous gut microbial composition is more plastic that previously anticipated. However, since antibiotic pretreatment counterintuitively interferes with the establishment of an exogenous community, such plasticity is likely conditioned more by the altered microbiome gut homeostasis caused by antibiotics than by the primary bacterial loss

&ldquo;Dispatcher, Can You Help Me? A Woman Is Giving Birth&rdquo;. A Pilot Study of Remote Video Assistance with Smart Glasses

Smart glasses (SG) could be a breakthrough in emergency situations, so the aim of this work was to assess the potential benefits of teleassistance with smart glasses (SG) from a midwife to a lifeguard in a simulated, unplanned, out-of-hospital birth (OHB). Thirty-eight lifeguards were randomized into SG and control (CG) groups. All participants were required to act in a simulated imminent childbirth with a maternal&ndash;fetal simulator (PROMPT Flex, Laerdal, Norway). The CG acted autonomously, while the SG group was video-assisted by a midwife through SG (Vuzix Blade, New York, NY, USA). The video assistance was based on the OHB protocol, speaking and receiving images on the SG. The performance time, compliance with the protocol steps, and perceived performance with the SG were evaluated. The midwife&rsquo;s video assistance with SG allowed 35% of the SG participants to perform the complete OHB protocol. No CG participant was able to perform it (p = 0.005). All OHB protocol variables were significantly better in the SG group than in the CG (p &lt; 0.05). Telemedicine through video assistance with SG is feasible so that a lifeguard with no knowledge of childbirth care can act according to the recommendations in a simulated, unplanned, uncomplicated OHB. Communication with the midwife by speaking and sending images to the SG is perceived as an important benefit to the performance

Activation of Immune and Defense Responses in the Intestinal Mucosa by Outer Membrane Vesicles of Commensal and Probiotic Escherichia coli Strains

The influence of microbiota in human health is well-known. Imbalances in microbiome structure have been linked to several diseases. Modulation of microbiota composition through probiotic therapy is an attempt to harness the beneficial effects of commensal microbiota. Although, there is wide knowledge of the responses induced by gut microbiota, the microbial factors that mediate these effects are not well-known. Gram-negative bacteria release outer membrane vesicles (OMVs) as a secretion mechanism of microbial factors, which have an important role in intercellular communication. Here, we investigated whether OMVs from the probiotic Escherichia coli strain Nissle 1917 (EcN) or the commensal E. coli strain ECOR12 trigger immune responses in various cellular models: (i) peripheral blood mononuclear cells (PBMCs) as a model of intestinal barrier disruption, (ii) apical stimulation of Caco-2/PMBCs co-culture as a model of intact intestinal mucosa, and (iii) colonic mucosa explants as an ex vivo model. Stimulations with bacterial lysates were also performed. Whereas, both OMVs and lysates activated expression and secretion of several cytokines and chemokines in PBMCs, only OMVs induced basolateral secretion and mRNA upregulation of these mediators in the co-culture model. We provide evidence that OMVs are internalized in polarized Caco-2 cells. The activated epithelial cells elicit a response in the underlying immunocompetent cells. The OMVs effects were corroborated in the ex vivo model. This experimental study shows that OMVs are an effective strategy used by beneficial gut bacteria to communicate with and modulate host responses, activating signaling events through the intestinal epithelial barrie