Assessing the viability of a synthetic bacterial consortium on the in vitro gut host-microbe interface

The interplay between host and microbiota has been long recognized and extensively described. The mouth is similar to other sections of the gastrointestinal tract, as resident microbiota occurs and prevents colonisation by exogenous bacteria. Indeed, more than 600 species of bacteria are found in the oral cavity, and a single individual may carry around 100 different at any time. Oral bacteria possess the ability to adhere to the various niches in the oral ecosystem, thus becoming integrated within the resident microbial communities, and favouring growth and survival. However, the flow of bacteria into the gut during swallowing has been proposed to disturb the balance of the gut microbiota. In fact, oral administration of P. gingivalis shifted bacterial composition in the ilea! microflora. We used a synthetic community as a simplified representation of the natural oral ecosystem, to elucidate the survival and viability of oral bacteria subjected to simulated gastrointestinal transit conditions. Fourteen species were selected, subjected to in vitro salivary, gastric, and intestinal digestion processes, and presented to a multicompartment cell model containing Caco-2 and HT29-MTX cells to simulate the gut mucosal epithelium. This model served to unravel the impact of swallowed bacteria on cells involved in the enterohepatic circulation. Using synthetic communities allows for controllability and reproducibility. Thus, this methodology can be adapted to assess pathogen viability and subsequent inflammation-associated changes, colonization capacity of probiotic mixtures, and ultimately, potential bacterial impact on the presystemic circulation

Short-term supplementation of celecoxib-shifted butyrate production on a simulated model of the gut microbial ecosystem and ameliorated in vitro inflammation

Celecoxib has been effective in the prevention and treatment of chronic inflammatory disorders through inhibition of altered cyclooxygenase-2 (COX-2) pathways. Despite the benefits, continuous administration may increase risk of cardiovascular events. Understanding microbiome-drug-host interactions is fundamental for improving drug disposition and safety responses of colon-targeted formulations, but little information is available on the bidirectional interaction between individual microbiomes and celecoxib. Here, we conducted in vitro batch incubations of human faecal microbiota to obtain a mechanistic proof-of-concept of the short-term impact of celecoxib on activity and composition of colon bacterial communities. Celecoxib-exposed microbiota shifted metabolic activity and community composition, whereas total transcriptionally active bacterial population was not significantly changed. Butyrate production decreased by 50% in a donor-dependent manner, suggesting that celecoxib impacts in vitro fermentation. Microbiota-derived acetate has been associated with inhibition of cancer markers and our results suggest uptake of acetate for bacterial functions when celecoxib was supplied, which potentially favoured bacterial competition for acetyl-CoA. We further assessed whether colon microbiota modulates anti-inflammatory efficacy of celecoxib using a simplified inflammation model, and a novel in vitro simulation of the enterohepatic metabolism. Celecoxib was responsible for only 5% of the variance in bacterial community composition but celecoxib-exposed microbiota preserved barrier function and decreased concentrations of IL-8 and CXCL16 in a donor-dependent manner in our two models simulating gut inflammatory milieu. Our results suggest that celecoxib-microbiome-host interactions may not only elicit adaptations in community composition but also in microbiota functionality, and these may need to be considered for guaranteeing efficient COX-2 inhibition

Sulfuric acid recovery from acid mine drainage by means of electrodialysis

In the present work the recovery of sulfuric acid from acid mine drainage by means of 3-compartment electrodialysis (ED) is evaluated. An effective recovery of sulfuric acid free from Fe(III) species was obtained in the anodic compartment as a result of the co-ion exclusion mechanism in the membranes. The difference in the pH and pSO42 − values between the membrane phase and the external electrolyte promotes the dissociation of complex species inside the membranes. This phenomenon impedes the transport of Fe(III) and sulfates in the form of complex ions toward the anodic and cathodic compartment, respectively. The current efficiency values of the anion-exchange membrane at different current densities were approximately constant with time. However, the increase in the recovery of acid decreases as the current increases. This result is explained by the shift in the equilibrium at the membrane/solution interface as more SO42 − ions cross the anionic membrane and, by the enhancement of the dissociation of water when the limiting current density is exceeded. The main limitation of the process is related to an abrupt increase in the cell voltage due to the formation of precipitates at the surface of the cation-exchange membrane.This work was supported by Ministerio de Economia y Competitividad (Spain) with the project number CTQ2012-37450-C02-01/PPQ. M.C. Marti-Calatayud is grateful to the Universitat Politecnica de Valencia for a postgraduate grant (Ref.: 2010-12). D.C. Buzzi wants to express her gratitude to CAPES (Brazil) for a postgraduate grant (Proc. BEX 8747/11-3).Martí Calatayud, MC.; Cardoso Buzzi, D.; García Gabaldón, M.; Ortega Navarro, EM.; Bernardes, A.; Suarez Tenorio, JA.; Pérez Herranz, V. (2014). Sulfuric acid recovery from acid mine drainage by means of electrodialysis. Desalination. 343:120-127. https://doi.org/10.1016/j.desal.2013.11.03112012734

Propionate-Producing Consortium Restores Antibiotic-Induced Dysbiosis in a Dynamic in vitro Model of the Human Intestinal Microbial Ecosystem

Metabolic syndrome is a growing public health concern. Efforts at searching for links with the gut microbiome have revealed that propionate is a major fermentation product in the gut with several health benefits toward energy homeostasis. For instance, propionate stimulates satiety-inducing hormones, leading to lower energy intake and reducing weight gain and associated risk factors. In (disease) scenarios where microbial dysbiosis is apparent, gut microbial production of propionate may be decreased. Here, we investigated the effect of a propionogenic bacterial consortium composed of Lactobacillusplantarum, Bacteroidesthetaiotaomicron, Ruminococcusobeum, Coprococcuscatus, Bacteroidesvulgatus, Akkermansiamuciniphila, and Veillonellaparvula for its potential to restore in vitro propionate concentrations upon antibiotic-induced microbial dysbiosis. Using the mucosal simulator of the human intestinal microbial ecosystem (M-SHIME), we challenged the simulated colon microbiome with clindamycin. Addition of the propionogenic consortium resulted in successful colonization and subsequent restoration of propionate levels, while a positive effect on the mitochondrial membrane potential (ΔΨm) was observed in comparison with the controls. Our results support the development and application of next generation probiotics, which are composed of multiple bacterial strains with diverse functionality and phylogenetic background

High exposure to tacrolimus is associated to spontaneous remission of recurrent membranous nephropathy after kidney transplantation

Introduction We aimed to characterize the incidence and clinical presentation of membranous nephropathy (MN) after kidney transplantation (KT), and to assess allograft outcomes according to proteinuria rates and immunosuppression management. Methods Multicenter retrospective cohort study including patients from six Spanish centers who received a KT between 1991-2019. Demographic, clinical, and histological data were collected from recipients with biopsy-proven MN as primary kidney disease (n = 71) or MN diagnosed de novo after KT (n = 4). Results Up to 25.4% of patients with biopsy-proven MN as primary kidney disease recurred after a median time of 18.1 months posttransplant, without a clear impact on graft survival. Proteinuria at 3-months post-KT was a predictor for MN recurrence (rMN, HR 4.28; P = 0.008). Patients who lost their grafts had higher proteinuria during follow-up [1.0 (0.5-2.5) vs 0.3 (0.1-0.5) g/24 h], but only eGFR after recurrence treatment predicted poorer graft survival (eGFR < 30 ml/min: RR = 6.8). We did not observe an association between maintenance immunosuppression and recurrence diagnosis. Spontaneous remission after rMN was associated with a higher exposure to tacrolimus before recurrence (trough concentration/dose ratio: 2.86 vs 1.18; P = 0.028). Up to 94.4% of KT recipients received one or several treatments after recurrence onset: 22.2% rituximab, 38.9% increased corticosteroid dose, and 66.7% ACEi/ARBs. Only 21 patients had proper antiPLA2R immunological monitoring. Conclusions One-fourth of patients with biopsy-proven MN as primary kidney disease recurred after KT, without a clear impact on graft survival. Spontaneous remission after rMN was associated with a higher exposure to tacrolimus before recurrence.12 página

Análisis de resultados tras la adaptación a modalidad online de una práctica de una asignatura de 1º del Máster Universitario en Ingeniería Industrial

[EN] The pandemic caused by COVID19 has forced universities to transfer teaching to non-face-to-face mode at different moments in the 19-20 and 20-21 academic years. Although this type of teaching implies certain difficulties in any type of teaching, these are more critical in the case of laboratory practices, associated with the skills of handling of equipment and instrumentation. Some of the strategies most commonly used to adapt experimental practices to remote teaching are: the use of audiovisual resources (own-made or on the Internet), presentations with Powerpoint-type programs, and the analysis and discussion of results provided by teachers. In some more specific disciplines, virtual or remote control laboratories are used to teach laboratory practices. This work describes the strategies used to adapt in non-face-to-face mode a practice in a subject of the Master's Degree in Industrial Engineering, as well as the tools used to teach and evaluate the practice. Furthermore, it analyses the academic results achieved, and the possible influence of distance teaching on them. On the other hand, it analyzes the opinion of the lecturers regarding the modifications introduced, in view of their possible continuity in future courses.[ES] La pandemia provocada por la COVID19 ha obligado a las universidades a trasladar la docencia a modalidad no presencial en distintos momentos de los cursos académicos 2019-20 y 2020-21. Aunque esta modalidad de enseñanza supone ciertas dificultades en cualquier tipo de docencia, éstas son más críticas en el caso de las prácticas de laboratorio, por las competencias de manejo y manipulación de equipos e instrumentación. Algunas de las estrategias más comúnmente empleadas para adaptar prácticas experimentales a modalidad a distancia son: el empleo de recursos audiovisuales (propios o existentes en internet), las presentaciones con programas tipo Powerpoint, y el análisis y discusión de resultados facilitados por el profesorado. En algunas disciplinas más específicas, se hacen uso de laboratorios virtuales o por control remoto para impartir las prácticas de laboratorio. En este trabajo se describen las estrategias empleadas para adaptar a modo no presencial una práctica en una asignatura del Máster Universitario en Ingeniería Industrial. Se describen las herramientas utilizadas para impartir y evaluar la práctica, y se analizan los resultados académicos alcanzados, así cómo la posible influencia de la docencia a distancia en los mismos.Sancho Fernández, MP.; Cuartas Uribe, BE.; Belanche Paricio, MI.; Bes Piá, MA.; García Fayos, B.; Ferrer Polonio, E.; Rodríguez López, AD.... (2021). Análisis de resultados tras la adaptación a modalidad online de una práctica de una asignatura de 1º del Máster Universitario en Ingeniería Industrial. En IN-RED 2021: VII Congreso de Innovación Edicativa y Docencia en Red. Editorial Universitat Politècnica de València. 917-930. https://doi.org/10.4995/INRED2021.2021.13444OCS91793