RESUMEN
Various generic extraction methods have been used to determine pesticide residues, mycotoxins, and polycyclic aromatic hydrocarbons (PAHs) in food and animal feed to ensure consumer safety. However, these methods cannot extract all relevant compounds at an acceptable rate of recovery. This study presents a new extraction method. This new method facilitated the identification of 231 compounds, including 196 pesticides, 11 mycotoxins, and 24 PAHs over a broad range of polarities. These compounds were identified in various sample matrices, including those that are lipid-rich. The processed sample is first extracted with water, acetonitrile, formic acid, and heptane. The addition of ammonium formate results in separation into three phases and enables analysis of the aqueous phase. Solid-phase extraction clean-up procedures were performed as necessary followed by analysis by liquid or gas chromatography and mass spectrometry. Analyte recoveries were typically in the range of 70 - 120% with relative standard deviations below 20%.
Asunto(s)
Micotoxinas/análisis , Residuos de Plaguicidas/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Alimentación Animal , Animales , Cromatografía Líquida de Alta Presión , Alimentos , Análisis de los Alimentos , Cromatografía de Gases y Espectrometría de Masas/métodos , Extracción en Fase Sólida/métodosRESUMEN
While prolonged fasting induces significant metabolic changes in humans and mice, less is known about systems-wide metabolic changes in response to short-term feed deprivation, which is used in experimental animal studies prior to metabolic challenge tests. We here performed a systems biology-based investigation of connections between gut bacterial composition and function, inflammatory and metabolic parameters in the intestine, liver, visceral adipose tissue, blood and urine in high-fat fed, obese mice that were feed deprived up to 12 h. The systems-wide analysis revealed that feed deprivation linked to enhanced intestinal butyric acid production and expression of the gene encoding the pro-thermogenic uncoupling protein UCP1 in visceral adipose tissue of obese mice. Ucp1 expression was also positively associated with Il33 expression in ileum, colon and adipose tissue as well as with the abundance of colonic Porphyromonadaceae, the latter also correlating to cecal butyric acid levels. Collectively, the data highlighted presence of a multi-tiered system of inter-tissue communication involving intestinal, immune and metabolic functions which is affected by feed deprivation in obese mice, thus pointing to careful use of short-feed deprivation in metabolic studies using obese mice.
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Inanición/patología , Biología de Sistemas , Animales , Bacterias/metabolismo , Ácido Butírico/metabolismo , Ciego/metabolismo , Fermentación , Microbioma Gastrointestinal , Grasa Intraabdominal/metabolismo , Masculino , Ratones Endogámicos C57BL , Ratones Obesos , Análisis Multivariante , Factores de Tiempo , Proteína Desacopladora 1/metabolismoRESUMEN
Staphylococcus delphini is one of the most common pathogens isolated from mink infections, especially dermatitis. Tylosin (TYL) is used frequently against these infections, although no evidence-based treatment regimen exists. This study aimed to explore the dosage of TYL for infections caused by S. delphini in mink. Two animal experiments with a total of 12 minks were conducted to study the serum pharmacokinetic (PK) characteristics of TYL in mink after 10 mg/kg IV and oral dosing, respectively. The concentration of TYL in serum samples collected before and eight times during 24 h after TYL administration was quantitated with liquid chromatography quadrupole time-of-flight mass spectrometry, and the TYL disposition was analyzed using non-linear mixed effect analysis. The pharmacodynamics (PD) of TYL against S. delphini were studied using semi-mechanistic modeling of in vitro time-kill experiments. PKPD modeling and simulation were done to establish the PKPD index and dosage regimen. The disposition of TYL was described by a two-compartmental model. The area under the free concentration-time curve of TYL over the minimum inhibitory concentration of S. delphini (fAUC/MIC) was determined as PKPD index with breakpoints of 48.9 and 98.7 h for bacteriostatic and bactericidal effect, respectively. The calculated daily oral dose of TYL was 2378 mg/kg, which is 238-fold higher than the currently used TYL oral dosage regimen in mink (10 mg/kg). Accordingly, sufficient TYL concentrations are impossible to achieve in mink plasma, and use of this drug for extra-intestinal infections in this animal species must be discouraged.
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Antibacterianos/farmacología , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus/efectos de los fármacos , Tilosina/farmacología , Animales , Antibacterianos/farmacocinética , Masculino , Pruebas de Sensibilidad Microbiana/veterinaria , Visón , Staphylococcus/fisiología , Tilosina/farmacocinéticaRESUMEN
Antimicrobial agents are used extensively off-label in mink, as almost no agents are registered for this animal species. Pharmacokinetic (PK) and pharmacodynamic (PD) data are required to determine antimicrobial dosages specifically targeting mink bacterial pathogens. The aims of this study were to assess, in a PKPD framework, the empirical dosage regimen for a combination of trimethoprim (TMP) and sulfadiazine (SDZ) in mink, and secondarily to produce data for future setting of clinical breakpoints. TMP and SDZ PK parameters were obtained experimentally in 22 minks following IV or oral administration of TMP/SDZ (30 mg/kg, i.e. 5 mg/kg TMP and 25 mg/kg SDZ). fAUC/MIC with a target value of 24 hr was selected as the PKPD index predictive of TMP/SDZ efficacy. Using a modeling approach, PKPD cutoffs for TMP and SDZ were determined as 0.062 and 16 mg/L, respectively. By incorporating an anticipated potentiation effect of SDZ on TMP against Escherichia coli and Staphylococcus delphini, the PKPD cutoff of TMP was revised to 0.312 mg/L, which is above the tentative epidemiological cutoffs (TECOFF) for these species. The current empirical TMP/SDZ dosage regimen (30 mg/kg, PO, once daily) therefore appears adequate for treatment of wild-type E. coli and S. delphini infections in mink.
Asunto(s)
Antiinfecciosos Urinarios/farmacocinética , Infecciones por Escherichia coli/veterinaria , Visón , Infecciones Estafilocócicas/veterinaria , Staphylococcus , Sulfadiazina/farmacocinética , Trimetoprim/farmacocinética , Animales , Antiinfecciosos Urinarios/administración & dosificación , Antiinfecciosos Urinarios/uso terapéutico , Área Bajo la Curva , Combinación de Medicamentos , Escherichia coli/efectos de los fármacos , Infecciones por Escherichia coli/tratamiento farmacológico , Semivida , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/microbiología , Sulfadiazina/administración & dosificación , Sulfadiazina/uso terapéutico , Trimetoprim/administración & dosificación , Trimetoprim/uso terapéuticoRESUMEN
Food can contain unwanted compounds and need to be analyzed for compounds like carcinogenic polycyclic aromatic hydrocarbons to ensure consumer safety. The analytes need to be extracted from the sample matrix and cleaned-up to enable detection. However, established methods for clean-up are labor intensive and have a high expenditure on organic solvents. Here, we show a newly developed micro-solid-phase extraction cartridge method to automate the clean-up for analysis of polycyclic aromatic hydrocarbons in sunflower oil using gas chromatography with quadrupole-orbitrap mass spectrometry with a TriPlus autosampler. This automated micro-solid-phase extraction cartridge method needs only 4 µL of vegetable oil sample and requires only 360 µL acetonitrile for elution, and, therefore, it needs only small amounts of organic solvent. Two different micro-solid-phase extraction cartridge methods were developed, one using two commercially available cartridges with florisil and octadecylsilane/Z-Sep/CarbonX, and the other method using one commercially available cartridge with florisil followed by one self-made cartridge with octadecylsilane/Z-Sep. The latter method showed successful lipid removal and was further validated for 22 of 24 polycyclic aromatic hydrocarbon compounds in sunflower oil at a spiked level of 1090 µg/kg with recoveries ranging from 53 to 118% and relative standard deviation below 22%. This method shows promising short-time clean-up with low expenditure of solvents.
Asunto(s)
Automatización , Análisis de los Alimentos , Contaminación de Alimentos/análisis , Aceites de Plantas/química , Hidrocarburos Policíclicos Aromáticos/análisis , Microextracción en Fase Sólida , Cromatografía de Gases y Espectrometría de MasasRESUMEN
Exposure to mixtures of endocrine disrupting chemicals may contribute to the rising incidence of hormone-related diseases in humans. Real-life mixtures are complex, comprised of chemicals with mixed modes of action, and essential knowledge is often lacking on how to group such chemicals into cumulative assessment groups, which is an essential prerequisite to conduct a chemical mixture risk assessment. We investigated if mixtures of chemicals with diverse endocrine modes of action can cause mixture effects on hormone sensitive endpoints in developing and adult rat offspring after perinatal exposure. Wistar rats were exposed during pregnancy and lactation simultaneously to either bisphenol A and butylparaben (Emix), diethylhexyl phthalate and procymidone (Amix), or a mixture of all four substances (Totalmix). In male offspring, the anogenital distance was significantly reduced and nipple retention increased in animals exposed to Amix and Totalmix, and the mixture effects were well approximated by the dose addition model. The combination of Amix and Emix responded with more marked changes on these and other endocrine-sensitive endpoints than each binary mixture on its own. Sperm counts were reduced by all exposures. These experimental outcomes suggest that the grouping of chemicals for mixture risk assessment should be based on common health outcomes rather than only similar modes or mechanisms of action. Mechanistic-based approaches such as the concept of Adverse Outcome Pathway (AOP) can provide important guidance if both the information on shared target tissues and the information on shared mode/mechanism of action are taken into account.
Asunto(s)
Dietilhexil Ftalato , Disruptores Endocrinos , Antagonistas de Andrógenos , Animales , Disruptores Endocrinos/toxicidad , Femenino , Humanos , Masculino , Embarazo , Ratas , Ratas Wistar , Medición de RiesgoRESUMEN
LC/ESI/MS is the technique of choice for qualitative and quantitative food monitoring; however, analysis of a large number of compounds is challenged by the availability of standard substances. The impediment of detection of food contaminants has been overcome by the suspect and non-targeted screening. Still, the results from one laboratory cannot be compared with the results of another laboratory as quantitative results are required for this purpose. Here we show that the results of the suspect and non-targeted screening for pesticides can be made quantitative with the aid of in silico predicted electrospray ionization efficiencies and this allows direct comparison of the results obtained in two different laboratories. For this purpose, six cereal matrices were spiked with 134 pesticides and analysed in two independent labs; a high correlation for the results with the R2 of 0.85.
Asunto(s)
Cromatografía Liquida/normas , Grano Comestible/química , Análisis de los Alimentos/normas , Contaminación de Alimentos/análisis , Plaguicidas/análisis , Espectrometría de Masa por Ionización de Electrospray/normas , Cromatografía Liquida/métodos , Simulación por Computador , Dinamarca , Estonia , Análisis de los Alimentos/métodos , Laboratorios , Espectrometría de Masa por Ionización de Electrospray/métodosRESUMEN
Azoles are effective antifungal agents used in both medicine and agriculture. They typically work by inhibiting cytochrome P450 enzymes, primarily CYP51 of the ergosterol biosynthesis pathway, thus damaging the fungal cell membrane. However, apart from their desired antifungal properties, several azoles also exhibit endocrine disrupting properties in mammals, both in vitro and in vivo. Here, we have tested two currently used agricultural azole fungicides, triticonazole and flusilazole, for their in vitro anti-androgenic activity and potential effects on reproductive parameters. Both fungicides showed strong androgen receptor (AR) antagonism and disruption of steroid biosynthesis in vitro. Following gestational exposure to flusilazole (15 or 45â¯mg/kgâ¯bw/day) or triticonazole (150 or 450â¯mg/kgâ¯bw/day) in time-mated Sprague Dawley rats, triticonazole induced shorter male anogenital distance (AGD). Flusilazole exposure did not affect the AGD, but altered fetal male blood hormone profile, with increased androstenedione and decreased estrone levels. Flusilazole and triticonazole have dissimilar effects on reproductive parameters in vivo, but both show endocrine disrupting activities.
Asunto(s)
Ciclopentanos/toxicidad , Disruptores Endocrinos/toxicidad , Fungicidas Industriales/toxicidad , Silanos/toxicidad , Triazoles/toxicidad , Antagonistas de Andrógenos , Androstenodiona , Animales , Antifúngicos , Azoles , Masculino , Ratas , Ratas Sprague-Dawley , Reproducción/efectos de los fármacosRESUMEN
Treatment of mink kits with pre-weaning diarrhea (PWD) can be time-consuming and expensive for the farmer, and the efficacy of the treatment procedure may be questioned. Evidence-based treatment protocols for application on affected animals at farms with outbreaks of PWD are lacking. In Denmark, the dams are sometimes treated with amoxicillin, however, it is unknown if it is passed on to the mink kits via the milk. The aim of the present study was to investigate if amoxicillin is transferred via the milk to the kits after oral (PO) and intramuscular (IM) treatment, respectively, of the dam. Moreover, we estimated the concentrations of amoxicillin continuously in serum from the kits up to 8â¯h after administration. The concentration of amoxicillin was not affected by the route of administration (Pâ¯=â¯.64) and serum reached the highest level after 8â¯h (34â¯ng/mL, CI95%â¯=â¯[24.3-47.7]). The serum concentrations of amoxicillin in the mink kits achieved within 8â¯h were judged too low to exert antimicrobial impact on relevant bacterial species.
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Amoxicilina/farmacocinética , Animales Lactantes/metabolismo , Antibacterianos/farmacocinética , Leche/química , Visón/metabolismo , Administración Oral , Amoxicilina/sangre , Crianza de Animales Domésticos , Animales , Antibacterianos/sangre , Cromatografía Liquida , Femenino , Inyecciones Intramusculares/veterinariaRESUMEN
OBJECTIVE: To investigate whether a whole grain diet alters the gut microbiome and insulin sensitivity, as well as biomarkers of metabolic health and gut functionality. DESIGN: 60 Danish adults at risk of developing metabolic syndrome were included in a randomised cross-over trial with two 8-week dietary intervention periods comprising whole grain diet and refined grain diet, separated by a washout period of ≥6 weeks. The response to the interventions on the gut microbiome composition and insulin sensitivity as well on measures of glucose and lipid metabolism, gut functionality, inflammatory markers, anthropometry and urine metabolomics were assessed. RESULTS: 50 participants completed both periods with a whole grain intake of 179±50 g/day and 13±10 g/day in the whole grain and refined grain period, respectively. Compliance was confirmed by a difference in plasma alkylresorcinols (p<0.0001). Compared with refined grain, whole grain did not significantly alter glucose homeostasis and did not induce major changes in the faecal microbiome. Also, breath hydrogen levels, plasma short-chain fatty acids, intestinal integrity and intestinal transit time were not affected. The whole grain diet did, however, compared with the refined grain diet, decrease body weight (p<0.0001), serum inflammatory markers, interleukin (IL)-6 (p=0.009) and C-reactive protein (p=0.003). The reduction in body weight was consistent with a reduction in energy intake, and IL-6 reduction was associated with the amount of whole grain consumed, in particular with intake of rye. CONCLUSION: Compared with refined grain diet, whole grain diet did not alter insulin sensitivity and gut microbiome but reduced body weight and systemic low-grade inflammation. TRIAL REGISTRATION NUMBER: NCT01731366; Results.
Asunto(s)
Microbioma Gastrointestinal , Inflamación/sangre , Pérdida de Peso , Granos Enteros , Adulto , Anciano , Glucemia/metabolismo , Estudios Cruzados , Dinamarca , Dieta , Ingestión de Energía , Heces/microbiología , Femenino , Humanos , Inflamación/dietoterapia , Resistencia a la Insulina , Interleucina-6/sangre , Lípidos/sangre , Masculino , Metabolómica , Persona de Mediana EdadRESUMEN
Intergenerational transmission of bacteria during birth initiates the natural successional development of the intestinal microbiota in mammals. This process can be disrupted by antibiotic exposure, potentially affecting early-life microbiota-dependent metabolic programming. In the present study, we specifically investigate the metabolic consequences of exposing neonate Wistar rats to an antibiotic-perturbed low-diversity microbiota from birth until weaning, without exposing the pups directly to antibiotics. Here, we show that pups born from both amoxicillin and vancomycin-treated dams gain less weight than controls. This was concordant with lower feed intake as well as increased colonic expression of the PYY satiety hormone gene at weaning. The weight difference persists into adulthood even though the initial differences in gut microbiota subsided. Our results demonstrate that early-life exposure to an antibiotic-perturbed low-diversity microbiota is sufficient to cause changes in body weight persisting into adulthood.
RESUMEN
Dietary gluten causes severe disorders like celiac disease in gluten-intolerant humans. However, currently understanding of its impact in tolerant individuals is limited. Our objective was to test whether gliadin, one of the detrimental parts of gluten, would impact the metabolic effects of an obesogenic diet. Mice were fed either a defined high-fat diet (HFD) containing 4% gliadin (n = 20), or a gliadin-free, isocaloric HFD (n = 20) for 23 weeks. Combined analysis of several parameters including insulin resistance, histology of liver and adipose tissue, intestinal microbiota in three gut compartments, gut barrier function, gene expression, urinary metabolites and immune profiles in intestinal, lymphoid, liver and adipose tissues was performed. Mice fed the gliadin-containing HFD displayed higher glycated hemoglobin and higher insulin resistance as evaluated by the homeostasis model assessment, more hepatic lipid accumulation and smaller adipocytes than mice fed the gliadin-free HFD. This was accompanied by alterations in the composition and activity of the gut microbiota, gut barrier function, urine metabolome, and immune phenotypes within liver and adipose tissue. Our results reveal that gliadin disturbs the intestinal environment and affects metabolic homeostasis in obese mice, suggesting a detrimental effect of gluten intake in gluten-tolerant subjects consuming a high-fat diet.
Asunto(s)
Microbioma Gastrointestinal , Gliadina/administración & dosificación , Homeostasis , Adipocitos/patología , Tejido Adiposo/metabolismo , Tejido Adiposo/patología , Animales , Tamaño de la Célula , Dieta Alta en Grasa , Regulación de la Expresión Génica , Glucosa/metabolismo , Inflamación/patología , Mediadores de Inflamación/metabolismo , Intestinos/microbiología , Intestinos/patología , Metabolismo de los Lípidos , Hígado/metabolismo , Masculino , Metaboloma , Ratones Endogámicos C57BL , Modelos Biológicos , Fenotipo , OrinaRESUMEN
Microbiota transplantation to germ-free animals is a powerful method to study involvement of gut microbes in the aetiology of metabolic syndrome. Owing to large interpersonal variability in gut microbiota, studies with broad coverage of donors are needed to elucidate the establishment of human-derived microbiotas in mice, factors affecting this process and resulting impact on metabolic health. We thus transplanted faecal microbiotas from humans (16 obese and 16 controls) separately into 64 germ-free Swiss Webster mice caged in pairs within four isolators, with two isolators assigned to each phenotype, thereby allowing us to explore the extent of microbial spread between cages in a well-controlled environment. Despite high group-wise similarity between obese and control human microbiotas, transplanted mice in the four isolators developed distinct gut bacterial composition and activity, body mass gain, and insulin resistance. Spread of microbes between cages within isolators interacted with establishment of the transplanted microbiotas in mice, and contributed to the transmission of metabolic phenotypes. Our findings highlight the impact of donor variability and reveal that inter-individual spread of microbes contributes to the development of metabolic traits. This is of major importance for design of animal studies, and indicates that environmental transfer of microbes between individuals may affect host metabolic traits.
Asunto(s)
Microbioma Gastrointestinal , Obesidad/microbiología , Adolescente , Animales , Estudios de Casos y Controles , Niño , Trasplante de Microbiota Fecal , Heces/microbiología , Vida Libre de Gérmenes , Humanos , Resistencia a la Insulina , Lípidos/sangre , Masculino , Ratones , Obesidad/sangreRESUMEN
Humans are exposed to a large number of environmental chemicals in their daily life, many of which are readily detectable in blood or urine. It remains uncertain if these chemicals can cause adverse health effects when present together at low doses. In this study we have tested whether a mixture of 27 chemicals administered orally to juvenile male rats for three months could leave a pathophysiological footprint. The mixture contained metals, perfluorinated compounds, PCB, dioxins, pesticides, heterocyclic amines, phthalate, PAHs and others, with a combined dose of 0.16 (Low dose), 0.47 (Mid dose) or 1.6 (High dose) mg/kg bw/day. The lowest dose was designed with the aim of obtaining plasma or urine concentrations in rats at levels approaching those observed in humans. Some single congeners were administered at doses representative of combined doses for chemical groups. With this baseline, we found effects on weight, histology and gene expression in the liver, as well as changes to the blood plasma metabolome in all exposure groups, including low-dose. Additional adverse effects were observed in the higher dosed groups, including enlarged kidneys and alterations to the metabolome. No significant effects on reproductive parameters were observed.
Asunto(s)
Dioxinas/toxicidad , Contaminantes Ambientales/toxicidad , Compuestos Heterocíclicos/toxicidad , Metales/toxicidad , Plaguicidas/toxicidad , Ácidos Ftálicos/toxicidad , Bifenilos Policlorados/toxicidad , Animales , Peso Corporal/efectos de los fármacos , Dioxinas/sangre , Dioxinas/orina , Contaminantes Ambientales/sangre , Contaminantes Ambientales/orina , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Compuestos Heterocíclicos/sangre , Compuestos Heterocíclicos/orina , Humanos , Riñón/efectos de los fármacos , Riñón/metabolismo , Riñón/patología , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Masculino , Metaboloma , Metales/sangre , Metales/orina , Plaguicidas/sangre , Plaguicidas/orina , Fosfolípidos/sangre , Fosfolípidos/orina , Ácidos Ftálicos/sangre , Ácidos Ftálicos/orina , Bifenilos Policlorados/sangre , Bifenilos Policlorados/orina , Ratas , Bazo/efectos de los fármacos , Bazo/metabolismo , Bazo/patologíaRESUMEN
Information regarding the endogenous storages of vitamin D3 after cutaneous vitamin D synthesis compared to oral vitamin D3 supplementation is sparse. Furthermore it is not known whether vitamin D3 can be stored for later use during periods of shortages of vitamin D3. To investigate the endogenous storages of vitamin D3 two studies were carried out in Göttingen minipigs. In study 1 one group of minipigs (n=2) was daily exposed to UV light corresponding to 10-20 min of midday sun and another group (n=2) of pigs were fed up to 60 µg vitamin D3/day corresponding to 3.7-4.4 µg/kg body weight. Study 1 demonstrated that daily UV-exposure of minipigs stimulated the cutaneous synthesis of vitamin D3 and resulted in increasing serum vitamin D3 and 25-hydroxy vitamin D3, but also carcasses containing vitamin D3 and 25-hydroxy vitamin D3. The vitamin D3 content in adipose tissue from the UV-exposed minipigs was 150-260 ng/g and the content was 90-150 ng/g in the orally supplemented minipigs. In study 2, minipigs were UV-exposed daily for 49 days. Subsequently, one group (n=2) was fed a vitamin D-free diet and another group (n=2) was dosed daily with 13C-labeled vitamin D3. The concentrations of vitamin D3 and 25-hydroxy vitamin D3 in serum and skin- and subcutaneous adipose tissue biopsies were repeatedly monitored. Vitamin D3 and 25-hydroxy vitamin D3 were eliminated from the skin and the adipose tissue after UV-exposure was ceased. Supplementation of 13C-vitamin D3 did not seem to affect the decline in the endogenous vitamin D3 in the adipose tissue formed during UV-exposure.
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Calcifediol/metabolismo , Colecalciferol/deficiencia , Colecalciferol/metabolismo , Piel/metabolismo , Grasa Subcutánea/metabolismo , Rayos Ultravioleta , Animales , Porcinos , Porcinos EnanosRESUMEN
Authenticity and traceability of vanilla flavors were investigated using gas chromatography-isotope ratio mass spectrometry (GC-IRMS). Vanilla flavors produced by chemical synthesis (n = 2), fermentation (n = 1), and extracted from two different species of the vanilla orchid (n = 79) were analyzed. The authenticity of the flavor compound vanillin was evaluated on the basis of measurements of ratios of carbon stable isotopes (δ(13)C). It was found that results of δ(13)C for vanillin extracted from Vanilla planifolia and Vanilla tahitensis were significantly different (t test) and that it was possible to differentiate these two groups of natural vanillin from vanillin produced otherwise. Vanilla flavors were also analyzed for ratios of hydrogen stable isotopes (δ(2)H). A graphic representation of δ(13)C versus δ(2)H revealed that vanillin extracted from pods grown in adjacent geographic origins grouped together. Accordingly, values of δ(13)C and δ(2)H can be used for studies of authenticity and traceability of vanilla flavors.
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Aromatizantes/análisis , Contaminación de Alimentos/análisis , Extractos Vegetales/análisis , Vanilla/química , Benzaldehídos , Isótopos de Carbono/análisis , Deuterio/análisis , Control de Calidad , Vanilla/clasificaciónRESUMEN
Prebiotic oligosaccharides are defined by their selective stimulation of growth and/or activity of bacteria in the digestive system in ways claimed to be beneficial for health. However, apart from the short chain fatty acids, little is known about bacterial metabolites created by fermentation of prebiotics, and the significance of the size of the oligosaccharides remains largely unstudied. By in vitro fermentations in human fecal microbial communities (derived from six different individuals), we studied the effects of high-mass (HA, >1 kDa), low-mass (LA, <1 kDa) and mixed (BA) sugar beet arabino-oligosaccharides (AOS) as carbohydrate sources. Fructo-oligosaccharides (FOS) were included as reference. The changes in bacterial communities and the metabolites produced in response to incubation with the different carbohydrates were analyzed by quantitative PCR (qPCR) and Liquid Chromatography-Mass Spectrometry (LC-MS), respectively. All tested carbohydrate sources resulted in a significant increase of Bifidobacterium spp. between 1.79 fold (HA) and 1.64 fold (FOS) in the microbial populations after fermentation, and LC-MS analysis suggested that the bifidobacteria contributed to decomposition of the arabino-oligosaccharide structures, most pronounced in the HA fraction, resulting in release of the essential amino acid phenylalanine. Abundance of Lactobacillus spp. correlated with the presence of a compound, most likely a flavonoid, indicating that lactobacilli contribute to release of such health-promoting substances from plant structures. Additionally, the combination of qPCR and LC-MS revealed a number of other putative interactions between intestinal microbes and the oligosaccharides, which contributes to the understanding of the mechanisms behind prebiotic impact on human health.
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Bacterias/efectos de los fármacos , Tracto Gastrointestinal/microbiología , Metaboloma , Microbiota/efectos de los fármacos , Oligosacáridos/metabolismo , Filogenia , Prebióticos , Adulto , Bacterias/genética , Bacterias/metabolismo , Cromatografía Liquida , Femenino , Fermentación , Humanos , Masculino , Espectrometría de Masas , Persona de Mediana Edad , Peso Molecular , Oligosacáridos/química , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
We compared fecal microbial communities derived either from Ulcerative Colitis (UC) patients in remission (n = 4) or in relapse (n = 4), or from healthy subjects (n = 4). These communities were used for inoculation of a dynamic in vitro gut model, which contained integrated mucin-covered microcosms. We found that the microbiota of the 'mucus' largely differed from that of the 'lumen'. This was partly due to decreased mucus-associated populations of lactic acid producing bacterial populations (LAB), as LAB originating from UC patients had a significantly decreased capacity to colonize the mucin-covered microcosms as compared to those originating from healthy subjects. We found significant differences between the metabolomes of UC patients in relapse and remission, respectively, while the metabolome of patients in remission resembled that of healthy subjects. These novel findings constitute an important contribution to the understanding of the complex etiology of UC.