Fate and Complex Pathogenic Effects of Dioxins and Polychlorinated Biphenyls in Obese Subjects before and after Drastic Weight Loss

BACKGROUND: In humans, persistent organic pollutants (POPs) are stored primarily in adipose tissue. Their total body burden and their contribution to obesity-associated diseases remain unclear. OBJECTIVES: We characterized POP total body burden and their redistribution in obese individuals before and after drastic weight loss and compared these values with a variety of molecular, biological, and clinical parameters. METHODS: Seventy-one obese subjects were enrolled and underwent bariatric surgery. Blood and adipose tissue samples were obtained at different times from these individuals as well as from 18 lean women. RESULTS: POP content (17 dioxins/furans and 18 polychlorinated biphenyl congeners) in different adipose tissue territories was similar, allowing us to assess total POP body burden from a single biopsy. Total POP body burden was 2 to 3 times higher in obese than in lean individuals. We also found increased expression of some POP target genes in obese adipose tissue. Drastic weight loss led to increased serum POPs and, within 6-12 months, to a significant 15% decrease in total polychlorinated biphenyl body burden. Importantly, serum POP levels were positively correlated with liver toxicity markers and lipid parameters, independently of age and body mass index. CONCLUSIONS: POP content in adipose tissue and serum correlate with biological markers of obesity-related dysfunctions. Drastic weight loss leads to a redistribution of POPs and to a moderate decrease of their total body burden

Valsartan Improves Adipose Tissue Function in Humans with Impaired Glucose Metabolism: A Randomized Placebo-Controlled Double-Blind Trial

<div><h3>Background</h3><p>Blockade of the renin-angiotensin system (RAS) reduces the incidence of type 2 diabetes mellitus. In rodents, it has been demonstrated that RAS blockade improved adipose tissue (AT) function and glucose homeostasis. However, the effects of long-term RAS blockade on AT function have not been investigated in humans. Therefore, we examined whether 26-wks treatment with the angiotensin II type 1 receptor blocker valsartan affects AT function in humans with impaired glucose metabolism (IGM).</p> <h3>Methodology/Principal Findings</h3><p>We performed a randomized, double-blind, placebo-controlled parallel-group study, in which 38 subjects with IGM were treated with valsartan (VAL, 320 mg/d) or placebo (PLB) for 26 weeks. Before and after treatment, an abdominal subcutaneous AT biopsy was collected for measurement of adipocyte size and AT gene/protein expression of angiogenesis/capillarization, adipogenesis, lipolytic and inflammatory cell markers. Furthermore, we evaluated fasting and postprandial AT blood flow (ATBF) (¹³³Xe wash-out), systemic inflammation and insulin sensitivity (hyperinsulinemic-euglycemic clamp). VAL treatment markedly reduced adipocyte size (<em>P</em><0.001), with a shift toward a higher proportion of small adipocytes. In addition, fasting (<em>P</em> = 0.043) and postprandial ATBF (<em>P</em> = 0.049) were increased, whereas gene expression of angiogenesis/capillarization, adipogenesis and macrophage infiltration markers in AT was significantly decreased after VAL compared with PLB treatment. Interestingly, the change in adipocyte size was associated with alterations in insulin sensitivity and reduced AT gene expression of macrophage infiltration markers. VAL did not alter plasma monocyte-chemoattractant protein (MCP)-1, TNF-α, adiponectin and leptin concentrations.</p> <h3>Conclusions/Significance</h3><p>26-wks VAL treatment markedly reduced abdominal subcutaneous adipocyte size and AT macrophage infiltration markers, and increased ATBF in IGM subjects. The VAL-induced decrease in adipocyte size was associated with reduced expression of macrophage infiltration markers in AT. Our findings suggest that interventions targeting the RAS may improve AT function, thereby contributing to a reduced risk of developing cardiovascular disease and type 2 diabetes.</p> <h3>Trial Registration</h3><p>Trialregister.nl NTR721 (ISRCTN Registry: ISRCTN<a href="http://www.controlled-trials.com/isrctn/pf/42786336">42786336</a>)</p> </div

Evidence of a causal and modifiable relationship between kidney function and circulating trimethylamine N-oxide

The host-microbiota co-metabolite trimethylamine N-oxide (TMAO) is linked to increased cardiovascular risk but how its circulating levels are regulated remains unclear. We applied "explainable" machine learning, univariate, multivariate and mediation analyses of fasting plasma TMAO concentration and a multitude of phenotypes in 1,741 adult Europeans of the MetaCardis study. Here we show that next to age, kidney function is the primary variable predicting circulating TMAO, with microbiota composition and diet playing minor, albeit significant, roles. Mediation analysis suggests a causal relationship between TMAO and kidney function that we corroborate in preclinical models where TMAO exposure increases kidney scarring. Consistent with our findings, patients receiving glucose-lowering drugs with reno-protective properties have significantly lower circulating TMAO when compared to propensity-score matched control individuals. Our analyses uncover a bidirectional relationship between kidney function and TMAO that can potentially be modified by reno-protective anti-diabetic drugs and suggest a clinically actionable intervention for decreasing TMAO-associated excess cardiovascular risk

GWAS on longitudinal growth traits reveals different genetic factors influencing infant, child, and adult BMI

Early childhood growth patterns are associated with adult health, yet the genetic factors and the developmental stages involved are not fully understood. Here, we combine genome-wide association studies with modeling of longitudinal growth traits to study the genetics of infant and child growth, followed by functional, pathway, genetic correlation, risk score, and colocalization analyses to determine how developmental timings, molecular pathways, and genetic determinants of these traits overlap with those of adult health. We found a robust overlap between the genetics of child and adult body mass index (BMI), with variants associated with adult BMI acting as early as 4 to 6 years old. However, we demonstrated a completely distinct genetic makeup for peak BMI during infancy, influenced by variation at the LEPR/LEPROT locus. These findings suggest that different genetic factors control infant and child BMI. In light of the obesity epidemic, these findings are important to inform the timing and targets of prevention strategies

GWAS on longitudinal growth traits reveals different genetic factors influencing infant, child, and adult BMI

This is the final version. Available on open access from AAAS via the DOI in this recordData and materials availability: All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials. Additional data related to this paper may be requested from the authors.Early childhood growth patterns are associated with adult health, yet the genetic factors and the developmental stages involved are not fully understood. Here, we combine genome-wide association studies with modeling of longitudinal growth traits to study the genetics of infant and child growth, followed by functional, pathway, genetic correlation, risk score, and colocalization analyses to determine how developmental timings, molecular pathways, and genetic determinants of these traits overlap with those of adult health. We found a robust overlap between the genetics of child and adult body mass index (BMI), with variants associated with adult BMI acting as early as 4 to 6 years old. However, we demonstrated a completely distinct genetic makeup for peak BMI during infancy, influenced by variation at the LEPR/LEPROT locus. These findings suggest that different genetic factors control infant and child BMI. In light of the obesity epidemic, these findings are important to inform the timing and targets of prevention strategies.Medical Research Council (MRC)Wellcome TrustNational Institutes of Health (NIH)Danish National Research FoundationLundbeck FoundationDanish Medical Research Counci

Characterization of the Gut Microbiota in Individuals with Overweight or Obesity during a Real-World Weight Loss Dietary Program: A Focus on the Bacteroides 2 Enterotype

Background: Dietary intervention is a cornerstone of weight loss therapies. In obesity, a dysbiotic gut microbiota (GM) is characterized by high levels of Bacteroides lineages and low diversity. We examined the GM composition changes, including the Bacteroides 2 enterotype (Bact2), in a real-world weight loss study in subjects following a high-protein hypocaloric diet with or without a live microorganisms (LMP) supplement. Method: 263 volunteers were part of this real-world weight loss program. The first phase was a high-protein low-carbohydrate calorie restriction diet with or without LMP supplements. Fecal samples were obtained at baseline and after 10% weight loss for 163 subjects. Metagenomic profiling was obtained by shotgun sequencing. Results: At baseline, the Bact2 enterotype was more prevalent in subjects with aggravated obesity and metabolic alterations. After weight loss, diversity increased and Bact2 prevalence decreased in subjects with lower GM diversity at baseline, notably in LMP consumers. Significant increases in Akkermansia muciniphila and Parabacteroides distasonis and significant decreases of Eubacterium rectale, Streptococcus thermophilus and Bifidobacterial lineages were observed after weight loss. Conclusions: Baseline microbiome composition is associated with differential changes in GM diversity and Bact2 enterotype prevalence after weight loss. Examining these signatures could drive future personalized nutrition efforts towards more favorable microbiome compositions

Gut microbiota and obesity : Interest of nanopore sequencing in the detection of metagenomic signatures in obesity and during nutritional interventions

Il est maintenant admis que le microbiote intestinal (MI) joue un rôle dans la physiopathologie de l'obésité. Plusieurs études menées récemment ont permis de stratifier les sujets obèses et en surpoids, en fonction de la richesse génétique et de la diversité de leur MI. Une association a été démontrée entre de la composition du MI et le phénotype clinique et biologique des sujets en situation d'obésité ainsi qu'avec les réponses aux interventions visant une perte de poids. Récemment, notre équipe avec le consortium européen MétaCardis a mis en évidence un profil particulier du microbiote, l'entérotype Bacteroides2 (bact2), enrichis chez des sujets sévèrement obèses et associé à une détérioration métabolique et inflammatoire.Il est donc intéressant de développer des méthodes de séquençage rapide du MI des sujets afin de pouvoir les stratifier et de tester l'hypothèse que l'état basal du MI pourrait être prédicteur de la réponse aux interventions diététiques ou chirurgicales. En lien avec ces objectifs, nous avons développé au sein du laboratoire et du service clinique un processus allant du recueil des selles de patients en situation de surpoids ou d'obésité jusqu'à la génération de données métagénomiques de séquençage avec l'outil MinION d'Oxford Nanopore Technologies (ONT). Nous avons par la suite, examiné le microbiote de deux cohortes, une bariatrique et l'autre d'une intervention de restriction calorique en vie réelle avec supplémentation en probiotiques, avec un focus sur l'entérotype Bact2 qui a été précédemment associé à une santé métabolique plus détériorée.Nous avons pu vérifier les résultats satisfaisants obtenus par séquençage Nanopore et également détecter certaines limites de cette technologie. Nos travaux dans une cohorte de 263 sujets en surpoids et obèses nous ont permis de démontrer la capacité de notre approche technologique à stratifier les sujets en fonction de la composition de leur MI. Par exemple, Bact2 était prédominant chez les sujets avec une obésité et des altérations métaboliques plus sévères. Après une perte de 10% du poids initial dans l'étude d‘intervention diététique (163 sujets appariés) et, en parallèle des améliorations métaboliques constatées, une diminution de la prévalence de Bact2 a été observée ainsi qu'une diminution de certaines bactéries pro-inflammatoires. Cette approche a été répétée chez des patients sévèrement obèses candidats à la chirurgie bariatrique (CB).En conclusion, nous avons mis en place une méthode d'évaluation rapide de la dysbiose dans l'obésité qui nous permet de détecter Bact2 qui pourrait être un prédicteur potentiel des réponses anthropométrique et métabolique aux interventions de perte de poids. En effet, la prédiction des réponses aux interventions diététiques et de CB pourrait être un outil important dans la pratique clinique, en améliorant la sélection des patients pour lesquels une prise en charge différente ou plus ciblée pourrait être envisagée.It is now accepted that the gut microbiota (GM) plays a role in the physiopathology of obesity. Several recent studies have shown it is possible to stratify subjects with obesity and overweight according to the gene richness and the diversity of their GM. An association has been demonstrated between the GM composition and the clinical and biological phenotype of obese subjects as well as with responses to interventions aimed weight loss. Recently, within the European MetaCardis consortium, our team revealed a particular profile of the microbiota, the enterotype Bacteroides2 (bact2), enriched in severely obese subjects and associated with metabolic and inflammatory deterioration.It is therefore interesting to develop methods for rapid sequencing of subjects' GM in order to stratify them and to test the hypothesis that the basal state of the GM could be predictive of the response to dietary or surgical interventions. In line with these objectives, we have developed a process that comprises collecting stools from patients with overweight or obese to the generation of metagenomic sequencing data with the MinION tool from Oxford Nanopore Technologies (ONT) within our medical department and laboratory. We then examined the GM of two cohorts: a bariatric surgery (BS) cohort and the other from a real-life calorie restriction intervention with probiotic supplementation, with a focus on the Bact2 enterotype, which has previously been associated with more deteriorated metabolic health.We were able to verify the satisfactory results obtained by Nanopore sequencing and also detect certain limitations of this technology. Our work in a cohort of 263 overweight and obese subjects allowed us to demonstrate the capacity of our technological approach to stratify subjects according to the composition of their GM. For example, Bact2 was predominant in subjects with obesity and more severe metabolic alterations. After 10% weight loss in the dietary intervention study (163 matched subjects), and in parallel with the metabolic improvements observed, a decrease in the prevalence of Bact2 was observed as well as a decrease in certain pro-inflammatory bacteria. This approach has been repeated in severely obese patients who are candidates for bariatric surgery.In conclusion, we have implemented a rapid assessment method for dysbiosis in obesity that allows us to detect Bact2 which could be a potential predictor of anthropometric and metabolic responses to weight loss interventions. Indeed, the prediction of responses to dietary and BS interventions could be an important tool in clinical practice by improving the selection of patients for whom a different or more targeted management could be considered

Microbiote intestinal et obésité : Identification d'une signature de la dysbiose chez le sujet obèse morbide par la technologie Oxford Nanopore.

L’Homme vit en symbiose avec une importante population microbienne qui colonise son tractus digestif et qui constitue son microbiote. La perturbation de ce mécanisme de symbiose induit une altération qualitative et fonctionnelle du microbiote intestinal provoquant ainsi une dysbiose qui pourrait expliquer certaines maladies auto-immunes ou inflammatoires telle que l’obésité.Chez l’Homme, plusieurs études ont été menées et ont démontrées que le microbiote intestinal pourrait relier les modifications des modes alimentaires aux altérations du métabolisme, du stockage énergétique et de l’inflammation chronique systémique et tissulaire caractérisant l’obésité. On a constaté par la suite, que pour une partie des sujets obèses, la diversité bactérienne était réduite, une diminution qui a été associée à des dysfonctionnements métaboliques plus marqués comparativement à des sujets obèses dont la diversité bactérienne est préservée. Au cours de la chirurgie, la dysbiose s’améliore mais n’est pas corrigée. Notre étude vise à caractériser par une nouvelle méthode (la technologie Nanopore), les anomalies du microbiote intestinal chez des patients à différents stade d’obésité et lors d’interventions visant à perdre du poids. Ce développement technologique permettrait dans le futur d’établir des moyens diagnostics de la dysbiose chez ces patients sévèrement obèses et plus généralement dans d’autres pathologies chroniques.Afin de pouvoir explorer le microbiote intestinal humain et pouvoir stratifier nos patients obèses en fonction de leur diversité bactérienne intestinale, j’ai développé au sein du laboratoire Nutriomique/Centre de Recherche en Nutrition Humaine Ile de France, une technologie de séquençage basée sur l’utilisation de l’outil MinION d’Oxford Nanopore. Pour cela j’ai mis au point un procédé de recueil des selles humaines qui permet de stabiliser l’ADN bactérien à température ambiante, une technique d’extraction de cet ADN et un protocole de séquençage qui permettent d’apporter une réponse quant au statut microbien du microbiote chez nos patients. J’ai réalisé une première validation de cette technologie par comparaison avec une autre technologie, le séquençage « SOLID », sur une même cohorte. J’ai pu obtenir la même stratification des patients en fonction de leurs diversité microbienne intestinale

Microbiote intestinal et obésité : Intérêt du séquençage par nanopore dans la détection des signatures métagénomiques dans l'obésité et lors d'interventions nutritionnelles

It is now accepted that the gut microbiota (GM) plays a role in the physiopathology of obesity. Several recent studies have shown it is possible to stratify subjects with obesity and overweight according to the gene richness and the diversity of their GM. An association has been demonstrated between the GM composition and the clinical and biological phenotype of obese subjects as well as with responses to interventions aimed weight loss. Recently, within the European MetaCardis consortium, our team revealed a particular profile of the microbiota, the enterotype Bacteroides2 (bact2), enriched in severely obese subjects and associated with metabolic and inflammatory deterioration.It is therefore interesting to develop methods for rapid sequencing of subjects' GM in order to stratify them and to test the hypothesis that the basal state of the GM could be predictive of the response to dietary or surgical interventions. In line with these objectives, we have developed a process that comprises collecting stools from patients with overweight or obese to the generation of metagenomic sequencing data with the MinION tool from Oxford Nanopore Technologies (ONT) within our medical department and laboratory. We then examined the GM of two cohorts: a bariatric surgery (BS) cohort and the other from a real-life calorie restriction intervention with probiotic supplementation, with a focus on the Bact2 enterotype, which has previously been associated with more deteriorated metabolic health.We were able to verify the satisfactory results obtained by Nanopore sequencing and also detect certain limitations of this technology. Our work in a cohort of 263 overweight and obese subjects allowed us to demonstrate the capacity of our technological approach to stratify subjects according to the composition of their GM. For example, Bact2 was predominant in subjects with obesity and more severe metabolic alterations. After 10% weight loss in the dietary intervention study (163 matched subjects), and in parallel with the metabolic improvements observed, a decrease in the prevalence of Bact2 was observed as well as a decrease in certain pro-inflammatory bacteria. This approach has been repeated in severely obese patients who are candidates for bariatric surgery.In conclusion, we have implemented a rapid assessment method for dysbiosis in obesity that allows us to detect Bact2 which could be a potential predictor of anthropometric and metabolic responses to weight loss interventions. Indeed, the prediction of responses to dietary and BS interventions could be an important tool in clinical practice by improving the selection of patients for whom a different or more targeted management could be considered.Il est maintenant admis que le microbiote intestinal (MI) joue un rôle dans la physiopathologie de l'obésité. Plusieurs études menées récemment ont permis de stratifier les sujets obèses et en surpoids, en fonction de la richesse génétique et de la diversité de leur MI. Une association a été démontrée entre de la composition du MI et le phénotype clinique et biologique des sujets en situation d'obésité ainsi qu'avec les réponses aux interventions visant une perte de poids. Récemment, notre équipe avec le consortium européen MétaCardis a mis en évidence un profil particulier du microbiote, l'entérotype Bacteroides2 (bact2), enrichis chez des sujets sévèrement obèses et associé à une détérioration métabolique et inflammatoire.Il est donc intéressant de développer des méthodes de séquençage rapide du MI des sujets afin de pouvoir les stratifier et de tester l'hypothèse que l'état basal du MI pourrait être prédicteur de la réponse aux interventions diététiques ou chirurgicales. En lien avec ces objectifs, nous avons développé au sein du laboratoire et du service clinique un processus allant du recueil des selles de patients en situation de surpoids ou d'obésité jusqu'à la génération de données métagénomiques de séquençage avec l'outil MinION d'Oxford Nanopore Technologies (ONT). Nous avons par la suite, examiné le microbiote de deux cohortes, une bariatrique et l'autre d'une intervention de restriction calorique en vie réelle avec supplémentation en probiotiques, avec un focus sur l'entérotype Bact2 qui a été précédemment associé à une santé métabolique plus détériorée.Nous avons pu vérifier les résultats satisfaisants obtenus par séquençage Nanopore et également détecter certaines limites de cette technologie. Nos travaux dans une cohorte de 263 sujets en surpoids et obèses nous ont permis de démontrer la capacité de notre approche technologique à stratifier les sujets en fonction de la composition de leur MI. Par exemple, Bact2 était prédominant chez les sujets avec une obésité et des altérations métaboliques plus sévères. Après une perte de 10% du poids initial dans l'étude d‘intervention diététique (163 sujets appariés) et, en parallèle des améliorations métaboliques constatées, une diminution de la prévalence de Bact2 a été observée ainsi qu'une diminution de certaines bactéries pro-inflammatoires. Cette approche a été répétée chez des patients sévèrement obèses candidats à la chirurgie bariatrique (CB).En conclusion, nous avons mis en place une méthode d'évaluation rapide de la dysbiose dans l'obésité qui nous permet de détecter Bact2 qui pourrait être un prédicteur potentiel des réponses anthropométrique et métabolique aux interventions de perte de poids. En effet, la prédiction des réponses aux interventions diététiques et de CB pourrait être un outil important dans la pratique clinique, en améliorant la sélection des patients pour lesquels une prise en charge différente ou plus ciblée pourrait être envisagée

Exploring Semi-Quantitative Metagenomic Studies Using Oxford Nanopore Sequencing: A Computational and Experimental Protocol

International audienceThe gut microbiome plays a major role in chronic diseases, of which several are characterized by an altered composition and diversity of bacterial communities. Large-scale sequencing projects allowed for characterizing the perturbations of these communities. However, translating these discoveries into clinical applications remains a challenge. To facilitate routine implementation of microbiome profiling in clinical settings, portable, real-time, and low-cost sequencing technologies are needed. Here, we propose a computational and experimental protocol for whole-genome semi-quantitative metagenomic studies of human gut microbiome with Oxford Nanopore sequencing technology (ONT) that could be applied to other microbial ecosystems. We developed a bioinformatics protocol to analyze ONT sequences taxonomically and functionally and optimized preanalytic protocols, including stool collection and DNA extraction methods to maximize read length. This is a critical parameter for the sequence alignment and classification. Our protocol was evaluated using simulations of metagenomic communities, which reflect naturally occurring compositional variations. Next, we validated both protocols using stool samples from a bariatric surgery cohort, sequenced with ONT, Illumina, and SOLiD technologies. Results revealed similar diversity and microbial composition profiles. This protocol can be implemented in a clinical or research setting, bringing rapid personalized whole-genome profiling of target microbiome species