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Labège, France

Paisse S.,VAIOMER SAS | Valle C.,VAIOMER SAS | Servant F.,VAIOMER SAS | Courtney M.,VAIOMER SAS | And 5 more authors.

BACKGROUND Recent studies have revealed that the blood of healthy humans is not as sterile as previously supposed. The objective of this study was to provide a comprehensive description of the microbiome present in different fractions of the blood of healthy individuals. STUDY DESIGN AND METHODS The study was conducted in 30 healthy blood donors to the French national blood collection center (Établissement Français du Sang). We have set up a 16S rDNA quantitative polymerase chain reaction assay as well as a 16S targeted metagenomics sequencing pipeline specifically designed to analyze the blood microbiome, which we have used on whole blood as well as on different blood fractions (buffy coat [BC], red blood cells [RBCs], and plasma). RESULTS Most of the blood bacterial DNA is located in the BC (93.74%), and RBCs contain more bacterial DNA (6.23%) than the plasma (0.03%). The distribution of 16S DNA is different for each fraction and spreads over a relatively broad range among donors. At the phylum level, blood fractions contain bacterial DNA mostly from the Proteobacteria phylum (more than 80%) but also from Actinobacteria, Firmicutes, and Bacteroidetes. At deeper taxonomic levels, there are striking differences between the bacterial profiles of the different blood fractions. CONCLUSION We demonstrate that a diversified microbiome exists in healthy blood. This microbiome has most likely an important physiologic role and could be implicated in certain transfusion-transmitted bacterial infections. In this regard, the amount of 16S bacterial DNA or the microbiome profile could be monitored to improve the safety of the blood supply. © 2016 AABB. Source

Lluch J.,VAIOMER SAS | Lluch J.,French National Institute for Agricultural Research | Servant F.,VAIOMER SAS | Paisse S.,VAIOMER SAS | And 11 more authors.

Background Substantial progress in high-throughput metagenomic sequencing methodologies has enabled the characterisation of bacteria from various origins (for example gut and skin). However, the recently-discovered bacterial microbiota present within animal internal tissues has remained unexplored due to technical difficulties associated with these challenging samples. Results We have optimized a specific 16S rDNA-targeted metagenomics sequencing (16S metabarcoding) pipeline based on the Illumina MiSeq technology for the analysis of bacterial DNA in human and animal tissues. This was successfully achieved in various mouse tissues despite the high abundance of eukaryotic DNA and PCR inhibitors in these samples. We extensively tested this pipeline on mock communities, negative controls, positive controls and tissues and demonstrated the presence of novel tissue specific bacterial DNA profiles in a variety of organs (including brain, muscle, adipose tissue, liver and heart). Conclusion The high throughput and excellent reproducibility of the method ensured exhaustive and precise coverage of the 16S rDNA bacterial variants present in mouse tissues. This optimized 16S metagenomic sequencing pipeline will allow the scientific community to catalogue the bacterial DNA profiles of different tissues and will provide a database to analyse host/bacterial interactions in relation to homeostasis and disease. © 2015 Lluch et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Source

Burcelin R.,French Institute of Health and Medical Research | Burcelin R.,University Paul Sabatier | Chabo C.,French Institute of Health and Medical Research | Chabo C.,University Paul Sabatier | And 7 more authors.

A new organ has emerged over the course of the last century: the intestinal microbiota. It is characterized by numerous functions provided by several billions of bacteria inhabiting and living in harmony in the lumen and in the mucosal layer of the intestinal epithelium. More than 4 million genes composed by more than 1 500 species interact with each other, with the host and the environment to set up a mutualistic ecological group. A nutritional stress will modify the terms of the symbiosis between the host and the microbiota for the control of energy homeostasis. It is now thought that the pandemic of diabetes and obesity, not being due to the sole variations of our genome, would be due to changes in our metagenome: our intestinal bacteria. This organ which genomic varies on an everyday basis is inherited from our mother and the closed environment at birth. The corresponding diversity, the rapid evolution of gene expression, its influence on metabolism, as well as the very recent discovery of the existence of an tissue microbiota within the host, open new therapeutic pharmacological and nutritional opportunities as well as the identification of very accurate biomarkers constituting a personalized metagenomic identity card. Hence, individualized medicine foresees its origin within the metagenome. Source

Amar J.,Toulouse University Hospital Center | Lange C.,French Institute of Health and Medical Research | Lange C.,University Paris - Sud | Payros G.,Bio Medical Research Federative Institute of Toulouse | And 13 more authors.

Aim: We recently described a human blood microbiome and a connection between this microbiome and the onset of diabetes. The aim of the current study was to assess the association between blood microbiota and incident cardiovascular disease. Methods and Results: D.E.S.I.R. is a longitudinal study with the primary aim of describing the natural history of the metabolic syndrome and its complications. Participants were evaluated at inclusion and at 3-, 6-, and 9-yearly follow-up visits. The 16S ribosomal DNA bacterial gene sequence, that is common to the vast majority of bacteria (Eubac) and a sequence that mostly represents Proteobacteria (Pbac), were measured in blood collected at baseline from 3936 participants. 73 incident cases of acute cardiovascular events, including 30 myocardial infarctions were recorded. Eubac was positively correlated with Pbac (r = 0.59; P<0.0001). In those destined to have cardiovascular complications, Eubac was lower (0.14±0.26 vs 0.12±0.29 ng/μl; P = 0.02) whereas a non significant increase in Pbac was observed. In multivariate Cox analysis, Eubac was inversely correlated with the onset of cardiovascular complications, (hazards ratio 0.50 95% CI 0.35-0.70) whereas Pbac (1.56, 95%CI 1.12-2.15) was directly correlated. Conclusion: Pbac and Eubac were shown to be independent markers of the risk of cardiovascular disease. This finding is evidence for the new concept of the role played by blood microbiota dysbiosis on atherothrombotic disease. This concept may help to elucidate the relation between bacteria and cardiovascular disease. © 2013 Amar et al. Source

Amar J.,University Paul Sabatier | Serino M.,Bio Medical Research Federative Institute of Toulouse | Serino M.,Toulouse University Hospital Center | Lange C.,French Institute of Health and Medical Research | And 25 more authors.

Aims/hypothesis: Evidence suggests that bacterial components in blood could play an early role in events leading to diabetes. To test this hypothesis, we studied the capacity of a broadly specific bacterial marker (16S rDNA) to predict the onset of diabetes and obesity in a general population. Methods: Data from an Epidemiological Study on the Insulin Resistance Syndrome (D.E.S.I.R.) is a longitudinal study with the primary aim of describing the history of the metabolic syndrome. The 16S rDNA concentration was measured in blood at baseline and its relationship with incident diabetes and obesity over 9 years of follow-up was assessed. In addition, in a nested case-control study in which participants later developed diabetes, bacterial phylotypes present in blood were identified by pyrosequencing of the overall 16S rDNA gene content. Results: We analysed 3,280 participants without diabetes or obesity at baseline. The 16S rDNA concentration was higher in those destined to have diabetes. No difference was observed regarding obesity. However, the 16S rDNA concentration was higher in those who had abdominal adiposity at the end of follow-up. The adjusted OR (95% CIs) for incident diabetes and for abdominal adiposity were 1.35 (1.11, 1.60), p=0.002 and 1.18 (1.03, 1.34), p=0.01, respectively. Moreover, pyrosequencing analyses showed that participants destined to have diabetes and the controls shared a core blood microbiota, mostly composed of the Proteobacteria phylum (85-90%). Conclusions/interpretation: 16S rDNA was shown to be an independent marker of the risk of diabetes. These findings are evidence for the concept that tissue bacteria are involved in the onset of diabetes in humans. © 2011 Springer-Verlag. Source

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