Cross-Regional View of Functional and Taxonomic Microbiota Composition in Obesity and Post-obesity Treatment Shows Country Specific Microbial Contribution.

Gut microbiota has been shown to have an important influence on host health. The microbial composition of the human gut microbiota is modulated by diet and other lifestyle habits and it has been reported that microbial diversity is altered in obese people. Obesity is a worldwide health problem that negatively impacts the quality of life. Currently, the widespread treatment for obesity is bariatric surgery. Interestingly, gut microbiota has been shown to be a relevant factor in effective weight loss after bariatric surgery. Since that the human gut microbiota of normal subjects differs between geographic regions, it is possible that rearrangements of the gut microbiota in dysbiosis context are also region-specific. To better understand how gut microbiota contribute to obesity, this study compared the composition of the human gut microbiota of obese and lean people from six different regions and showed that the microbiota compositions in the context of obesity were specific to each studied geographic location. Furthermore, we analyzed the functional patterns using shotgun DNA metagenomic sequencing and compared the results with other obesity-related metagenomic studies, we observed that microbial contribution to functional pathways were country-specific. Nevertheless, our study showed that although microbial composition of obese patients was country-specific, the overall metabolic functions appeared to be the same between countries, indicating that different microbiota components contribute to similar metabolic outcomes to yield functional redundancy. Furthermore, we studied the microbiota functional changes of obese patients after bariatric surgery, by shotgun metagenomics sequencing and observed that changes in functional pathways were specific to the type of obesity treatment. In all, our study provides new insights into the differences and similarities of obese gut microbiota in relation to geographic location and obesity treatments.

Protective Effect of an Avocado Peel Polyphenolic Extract Rich in Proanthocyanidins on the Alterations of Colonic Homeostasis Induced by a High-Protein Diet.

Avocado peel, a byproduct from the avocado pulp industry, is a promising source of polyphenolic compounds. We evaluated the effect of a proanthocyanidin-rich avocado peel polyphenol extract (AvPPE) on the composition and metabolic activity of human fecal microbiota cultured for 24 h in a bioreactor in the presence of high protein (HP) amounts and the effect of the resulting culture supernatants (CSs) on HT-29Glc-/+ and Caco-2 cells. AvPPE decreased the HP-induced production of ammonia, H2S, propionate, and isovalerate and increased that of indole and butyrate. Microbiota composition was marginally affected by HP, whileAvPPE increased the microorganisms/abundance of phylum Actinobacteria, families Coriobacteriaceae and Ruminococcaceae, and genus Faecalibacterium. AvPPE failed to prevent the HP-induced decrease of HT-29Glc-/+ cell viability and energy efficiency but prevented the HP-induced alterations of barrier function in Caco-2 cells. Additionally, the genotoxic effect of the CSs upon HT-29Glc-/+ was attenuated by AvPPE. Therefore, AvPPE may be considered as a promising product for improving colonic homeostasis.

Effect of a proanthocyanidin-rich polyphenol extract from avocado on the production of amino acid-derived bacterial metabolites and the microbiota composition in rats fed a high-protein diet.

The consumption of high-protein diets (HPDs) increases the flux of undigested proteins moving to the colon. These proteins are hydrolyzed by bacterial proteases and peptidases, releasing amino acids, which in turn are metabolized by the intestinal microbiota (IM) for protein synthesis and production of various metabolites that can exert positive or deleterious effects, depending on their concentrations, at the colonic or systemic level. On the other hand, proanthocyanidins are polymers of flavan-3-ols which cannot be absorbed at the intestinal level, accumulating in the colon where they are fermented by the IM producing metabolites that appear beneficial for colonocytes and also at the peripheral level. This study evaluated the effect of an avocado peel polyphenol extract (AvPPE) rich in proanthocyanidins on the production of cecal bacterial metabolites and microbiota composition in rats fed a HPD. Compared with the normal-protein (NP) group, HPD did not markedly affect the body weight gain of the animals, but increased the kidney weight. Additionally, the HPD induced a higher cecal concentration of ammonia (NH4+/NH3), hydrogen sulfide (H2S) and branched-chain fatty acids (BCFAs). The supplementation with AvPPE attenuated the production of H2S and increased the production of indole. On the other hand, the HPD affected the composition of the cecal microbiota, increasing the relative abundance of the genera Bacteroides and Lactobacillus, while decreasing Prevotella. The AvPPE counteracted the increase induced by the HPD on the genus Lactobacillus, and increased the relative abundance of [Prevotella]. Our results contribute towards explaining the health-promoting effects of proanthocyanidin-rich dietary foodstuffs including fruits and vegetables.

Gilz-Activin A as a Novel Signaling Axis Orchestrating Mesenchymal Stem Cell and Th17 Cell Interplay.

Mesenchymal stem cells (MSC) are highly immunosuppressive cells able to reduce chronic inflammation through the active release of mediators. Recently, we showed that glucocorticoid-induced leucine zipper (Gilz) expression by MSC is involved in their therapeutic effect by promoting the generation of regulatory T cells. However, the mechanisms underlying this pivotal role of Gilz remain elusive. Methods and Results In this study, we have uncovered evidence that Gilz modulates the phenotype and function of Th1 and Th17 cells likely by upregulating the level of Activin A and NO2 secreted by MSC. Adoptive transfer experiments sustained this Gilz-dependent suppressive effect of MSC on Th1 and Th17 cell functions. In immunoregulatory MSC, obtained by priming with IFN-γ and TNF-α, Gilz was translocated to the nucleus and bound to the promoters of inos and Activin ßA to induce their expression. The increased expression of Activin A directly impacted on Th17 cells fate by repressing their differentiation program through the activation of Smad3/2 and enhancing IL-10 production. Conclusion Our results reveal how Gilz controls inos and Activin ßA gene expression to ultimately assign immunoregulatory status to MSC able to repress the pathogenic Th17 cell differentiation program and uncover Activin A as a novel mediator of MSC in this process.

Distinct patterns in the gut microbiota after surgical or medical therapy in obese patients.

Bariatric surgery is highly successful in improving health compared to conventional dietary treatments. It has been suggested that the gut microbiota is a relevant factor in weight loss after bariatric surgery. Considering that bariatric procedures cause different rearrangements of the digestive tract, they probably have different effects on the gut microbiota. In this study, we compared the impact of medical treatment, sleeve gastrectomy and Roux-en-Y gastric bypass on the gut microbiota from obese subjects. Anthropometric and clinical parameters were registered before, 6 and 12 months after treatment. Fecal samples were collected and microbiota composition was studied before and six months post treatment using 16S rRNA gene sequencing and qPCR. In comparison to dietary treatment, changes in intestinal microbiota were more pronounced in patients subjected to surgery, observing a bloom in Proteobacteria. Interestingly, Bacteroidetes abundance was largely different after six months of each surgical procedure. Furthermore, changes in weight and BMI, or glucose metabolism, correlated positively with changes in these two phyla in these surgical procedures. These results indicate that distinct surgical procedures alter the gut microbiota differently, and changes in gut microbiota might contribute to health improvement. This study contributes to our understanding of the impact of weight loss surgery on the gut microbiota, and could be used to replicate this effect using targeted therapies.

Exposiciones rábicas en Colombia: evaluación del sistema de vigilancia desde los actores / Rabies exposures in Colombia: an evaluation by the actors of the surveillance system

Objetivo: identificar la percepción que tienen los actores frente a los atributos del sistema de vigilancia de las exposiciones rábicas para generar las recomendaciones que se requieran. Metodología: se utilizó la teoría fundada hasta análisis de categorías interpretativas; once entrevistas semiestructuradas enmarcadas en los atributos considerados por los Centros de Control y Prevención de Enfermedades (cdc) para la evaluación de sistemas de vigilancia se realizaron a personas con un rol activo (desde notificación hasta administrador del sistema), en los departamentos con mayor y menor notificación del evento en el país. Resultados: emergieron catorce categorías descriptivas relacionadas con los nueve atributos, sistema de vigilancia, rabia y propuestas para la mejora; de éstas, cinco categorías analíticas las enmarcan con recursos para la operación, experiencia, control directo de la rabia y papel de los actores en el proceso. Se destacó la importancia del sistema en la recolección de información en Salud Pública; se desconocen publicaciones relacionadas y se percibió como baja la participación de los actores en la planificación. Se manifestaron dificultades con la calidad de la información: clasificación de casos, afectando la representatividad y sensibilidad. La aceptabilidad se relaciona con las tareas del sistema y el tiempo dedicado al proceso. La oportunidad varía en procesos de notificación y ajuste. Conclusiones: la percepción sobre los atributos denota la articulación de conceptos del sistema y la experiencia adquirida; aspectos positivos como representatividad e historia y negativos relacionados con calidad, sensibilidad, utilidad y aceptabilidad. Recomendaciones: realizar publicaciones y mejorar la participación en la planificación del sistema.

Objective: to identify the perception of the actors regarding the attributes of the rabies exposures surveillance system to generate any required recommendations. Methodology: Grounded theory was used up to the analysis of interpretive categories. The researchers used semi-structured interviews in the Colombian departments with the highest and lowest notified instances of rabies exposure. The interviewees were individuals with active roles (i.e. ranging from personnel in charge of notifying to system administrators). Finally, the topic of the interviews was the attributes taken into account by the Centers for Disease Control and Prevention. Results: fourteen descriptive categories emerged. These were related to nine attributes, surveillance, rabies and proposals for improvement. Of these, five analytical categories are considered resources for operation, experience, direct control of rabies and the role of actors in the process. The importance of the system in gathering information on public health was highlighted. Related publications are disregarded, and the participation of the actors in the planning process was perceived as low. The participants mentioned shortcomings related to the quality of the information, i.e. case classification, which affects its representativeness and sensitivity. Acceptability was associated with system tasks and the time spent in the process. Timeliness varies in the notification and adjustment processes. Conclusions: The perception of the attributes shows the articulation of the system concepts with the lessons learned by the actors. Some positive aspects are history and representativeness, while some of the negative traits are related to quality, sensitivity, usefulness and acceptability. Recommendations: to publish and improve participation in the system planning process.