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Saint-Cyr M.J.,Residues and Resistance Unit | Perrin-Guyomard A.,Residues and Resistance Unit | Manceau J.,Scientific Support Unit | Houee P.,Residues and Resistance Unit | And 3 more authors.
Toxins | Year: 2015

Due to its toxic properties, high stability, and prevalence, the presence of deoxynivalenol (DON) in the food chain is a major threat to food safety and therefore a health risk for both humans and animals. In this study, experiments were carried out with sows and female rats to examine the kinetics of DON after intravenous and oral administration at 100 ± g/kg of body weight. After intravenous administration of DON in pigs, a two-compartment model with rapid initial distribution (0.030 ± 0.019 h) followed by a slower terminal elimination phase (1.53 ± 0.54 h) was fitted to the concentration profile of DON in pig plasma. In rats, a short elimination half-life (0.46 h) and a clearance of 2.59 L/h/kg were estimated by sparse sampling non-compartmental analysis. Following oral exposure, DON was rapidly absorbed and reached maximal plasma concentrations (Cmax) of 42.07 ± 8.48 and 10.44 ± 5.87 ± g/L plasma after (tmax) 1.44 ± 0.52 and 0.17 h in pigs and rats, respectively. The mean bioavailability of DON was 70.5% ± 25.6% for pigs and 47.3% for rats. In the framework of DON risk assessment, these two animal models could be useful in an exposure scenario in two different ways because of their different bioavailability. © 2015 by the authors; licensee MDPI, Basel, Switzerland.

Saint-Cyr M.J.,Residues and Resistance Unit | Perrin-Guyomard A.,Residues and Resistance Unit | Houee P.,Residues and Resistance Unit | Rolland J.-G.,Scientific Support Unit | Laurentie M.,Scientific Support Unit
PLoS ONE | Year: 2013

Background: Deoxynivalenol (DON), a mycotoxin produced by Fusarium species, is one of the most prevalent mycotoxins present in cereal crops worldwide. Due to its toxic properties, high stability and prevalence, the presence of DON in the food chain represents a health risk for both humans and animals. The gastrointestinal microbiota represents potentially the first target for these food contaminants. Thus, the effects of mycotoxins on the human gut microbiota is clearly an issue that needs to be addressed in further detail. Using a human microbiota-associated rat model, the aim of the present study was to evaluate the impact of a chronic exposure of DON on the composition of human gut microbiota. Methodology/Principal Findings: Four groups of 5 germ free male rats each, housed in 4 sterile isolators, were inoculated with a different fresh human fecal flora. Rats were then fed daily by gavage with a solution of DON at 100 μg/kg bw for 4 weeks. Fecal samples were collected at day 0 before the beginning of the treatment; days 7, 16, 21, and 27 during the treatment; and 10 days after the end of the treatment at day 37. DON effect was assessed by real-time PCR quantification of dominant and subdominant bacterial groups in feces. Despite a different intestinal microbiota in each isolator, similar trends were generally observed. During oral DON exposure, a significant increase of 0.5 log10 was observed for the Bacteroides/Prevotella group during the first 3 weeks of administration. Concentration levels for Escherichia coli decreased at day 27. This significant decrease (0.9 log10 CFU/g) remained stable until the end of the experiment. Conclusions/Significance: We have demonstrated an impact of oral DON exposure on the human gut microbiota composition. These findings can serve as a template for risk assessment studies of food contaminants on the human gut microbiota. © 2013 Saint-Cyr et al.

Saint-Cyr M.J.,Residues and Resistance Unit | Perrin-Guyomard A.,Residues and Resistance Unit | Houee P.,Residues and Resistance Unit | Vasseur M.V.,Residues and Resistance Unit | And 3 more authors.
Journal of AOAC International | Year: 2014

This study describes a novel validation procedure of real-time PCR based on accuracy profile to estimate bacterial concentrations in fecal samples. To assess the performance of the method, measurements of axenic fecal samples spiked with a measured quantity of known bacterial species (Bacteroides fragilis, Bifidobacterium adolescentis, Enterococcus faecium, and Escherichia coli) were performed under repeatability and intermediate precision conditions. Data collected were used to compute a tolerance interval that was compared to a defined acceptance interval. It is concluded that the method is valid and relevant for the studied validation range of 8.20-10.24 and 7.43-9.47 log 10 CFU/g of feces to ensure proper measurement of B. fragilis and E. coli, respectively. The LOQ is 8.20 and 7.43 log10 CFU/g of feces. In contrast, the method is not valid for the quantification of E. faecium and B. adolescentis, but by applying a correction factor of +0.63 log10 CFU/g, it can be considered valid for E. faecium. This correction is included in the final results. In conclusion, the accuracy profile is a statistical tool that is easy to use and totally adapted to validate real-time PCR. © 2014 Publishing Technology.

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