Sampling and storage study
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REPOSITORIES: ENA
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Project description:The aim of this study was to develop a suitable method to preserve fecal samples for metaproteomics analyses when flash-freezing is not an option. Fecal samples were collected from conventional adult C57BL/6 mice and combined into a fecal master mix. The fecal master mix was then split into 48 subsamples that were subjected to different preservation treatments. The following six preservation methods were tested: flash-freezing in liquid nitrogen followed by storage at -80°C, immersion in RNAlater® and storage at room temperature, immersion in RNAlater® and immediate storage at -80°C, immersion in 95% ethanol and storage at room temperature, immersion in a RNAlater-like buffer “NAP buffer” and storage at room temperature, and immersion in an autoclaved RNAlater-like buffer “Autoclaved NAP buffer” and storage at room temperature. Proteins were extracted from the samples after being stored for 1 and 4 weeks. There were 4 replicates per treatment and time-point. Samples were analyzed by LC-MS/MS and the data were analyzed with Proteome Discoverer against a large database of mouse microbiota protein sequences.
2021-11-25 | PXD024115 | Pride
Project description:Urine is a non-invasive biofluid for the identification of biomarkers to detect disease. In particular extracellular vesicles (EVs) have gained increased interest as a biomarker source, because the molecular content is protected against degradation. Clinical implementation on a daily basis requires protocols that inevitably includes short-term storage of the clinical samples, especially when samples are collected at home. However, little is known about the effect of delayed processing on the urinary EVs and their proteome. In the current study, we evaluated two different storage protocols. First, urine stored at 4˚C without any preservative, and second, a protocol compatible with at-home collection, urine with 40 mM EDTA stored at room temperature. For both conditions it was determined whether storage for 0, 2, 4 and 8 days leads to a change in the global urinary EV proteome profile using proteomics based on data-independent acquisition mass spectrometry. We show that EDTA does not affect the global proteome. Remarkably, the EV proteome was stable in both urine stored up to a week at room temperature with EDTA and in urine stored at 4˚C. These findings open up biomarker studies in urine collected via self-sampling.
2022-05-04 | PXD024324 | Pride
Project description:Data was collected on a LC-MS/MS system (c-18 column) positive mode. Data analyzing storage conditions of different storage collection devices for human fecal samples.
2019-11-07 | MSV000084554 | MassIVE
Project description:Fecal storage condition induces variations of microbial composition and interpretation of metagenomic analysis
| PRJEB33316 | ENA
Project description:Investigation of miRNA expression level changes in RBCs stored for 20 days, RBCs stored for 20 days with 1uM SNP, compared to healthy,male type O donors, and to explore the mechanism of storage lesions of RBC.
2016-09-15 | GSE86905 | GEO
Project description:Complex oligosaccharides found in human milk play a vital role in gut microbiome development for the human infant. Bovine milk oligosaccharides (BMO) have similar structures with those derived from human milk, but have not been well studied for their effects on the healthy adult human gut microbiome. Healthy human subjects consumed BMO over two-week periods at two different doses and provided fecal samples. Metatranscriptomics of fecal samples was conducted to determine microbial and host gene expression in response to the supplement. Fecal samples were also analyzed by mass spectrometry to determine levels of undigested BMO. No changes were observed in microbiome activity across all participants. Repeated sampling enabled subject-specific analyses: four of six participants had minor, yet statistically significant, changes in microbial activity. No significant change was observed in the gene expression of host cells in stool. Levels of BMO excreted in feces after supplementation were not significantly different from placebo and were not correlated with dosage or expressed microbial enzyme levels. Collectively, these data suggest that BMO is fully digested in the human gastrointestinal tract prior to stool collection. Participants’ gut microbiomes remained stable but varied between individuals. Additionally, the unaltered host transcriptome provides further evidence for the safety of BMO as a dietary supplement or food ingredient.
2020-02-18 | GSE108809 | GEO
Project description:Alterations in intestinal microbiota and intestinal short chain fatty acids profiles have been associated with the pathophysiology of obesity and insulin resistance. Whether intestinal microbiota dysbiosis is a causative factor in humans remains to be clarified We examined the effect of fecal microbial infusion from lean donors on the intestinal microbiota composition, glucose metabolism and small intestinal gene expression. Male subjects with metabolic syndrome underwent bowel lavage and were randomised to allogenic (from male lean donors with BMI<23 kg/m2, n=9) or autologous (reinfusion of own feces, n=9) fecal microbial transplant. Insulin sensitivity and fecal short chain fatty acid harvest were measured at baseline and 6 weeks after infusion. Intestinal microbiota composition was determined in fecal samples and jejunal mucosal biopsies were also analyzed for the host transcriptional response. Insulin sensitivity significantly improved six weeks after allogenic fecal microbial infusion (median Rd: from 26.2 to 45.3 μmol/kg.min, p<0.05). Allogenic fecal microbial infusion increased the overall amount of intestinal butyrate producing microbiota and enhanced fecal harvest of butyrate. Moreover, the transcriptome analysis of jejunal mucosal samples revealed an increased expression of genes involved in a G-protein receptor signalling cascade and subsequently in glucose homeostasis. Lean donor microbial infusion improves insulin sensitivity and levels of butyrate-producing and other intestinal microbiota in subjects with the metabolic syndrome. We propose a model wherein these bacteria provide an attractive therapeutic target for insulin resistance in humans. (Netherlands Trial Register NTR1776).
2020-10-28 | GSE30854 | GEO
Project description:With the technological advances of the last decade, it is now feasible to analyze environmental samples of vast complexity, such as human stool specimen, using meta-omics techniques like metaproteomics. Still the most sophisticated, sensitive instruments can only extract information that a sample contains in the first place. This highlights the need for initial sample preparation to preserve as much unaltered information as possible. Yet little is known about the effects different processing approaches have on the final analysis results. This study analyzes human stool samples applying metaproteomics and shows that the initial sample storage has a massive effect on the taxonomic composition of proteins identified. The findings are backed up by the results of the metagenomics analysis of the same samples. This suggests, that great care should be taken in choosing storage conditions for (omics) studies, as well as in comparing the results of experiments with different initial processing.
2019-09-26 | PXD014482 | Pride
Project description:<p><strong>BACKGROUND:</strong> Stool metabolites provide essential insights into the function of the gut microbiome. The current gold standard for storage of stool samples for metabolomics is flash-freezing at - 80 °C which can be inconvenient and expensive. Ambient temperature storage of stool is more practical, however no available methodologies adequately preserve the metabolomic profile of stool. A novel sampling kit (OMNImet.GUT; DNA Genotek, Inc.) was introduced for ambient temperature storage and stabilization of feces for metabolomics; we aimed to test the performance of this kit vs flash-freezing. To do this stool was collected from an infant's diaper was divided into 2 aliquots: 1) flash-frozen and 2) stored in an OMNImet.GUT tube at ambient temperature for 3-4 days. Samples from the same infant were collected at 2 different timepoints to assess metabolite changes over time. Subsequently, all samples underwent metabolomic analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS).</p><p><strong>RESULTS:</strong> Paired fecal samples (flash-frozen and ambient temperature) from 16 infants were collected at 2 timepoints (32 individual samples, 64 aliquots). Similar numbers of metabolites were detected in both the frozen and ambient temperature samples (1126 in frozen, 1107 in ambient temperature, 1064 shared between sample types). Metabolite abundances were strongly correlated between storage methods (median Spearman correlation Rs = 0.785 across metabolites). Hierarchical clustering analysis and principal component analysis showed that samples from the same individuals at a given timepoint clustered closely, regardless of the storage method. Repeat samples from the same individual were compared by paired t-test, separately for the frozen and OMNImet.GUT. The number of metabolites in each biochemical class that significantly changed (p < 0.05) at timepoint 2 relative to timepoint 1 was similar in flash-frozen vs ambient temperature storage. Changes in microbiota modified metabolites over time were also consistent across both methodologies.</p><p><strong>CONCLUSION:</strong> Ambient temperature storage and stabilization of stool in the OMNImet.GUT device yielded comparable metabolomic results to flash freezing in terms of 1) the identity and abundance of detected biochemicals 2) the distinct metabolomic profiles of subjects and 3) changes in metabolites over time that are plausibly microbiota-induced. This method potentially provides a more convenient, less expensive home collection and storage option for stool metabolomic analysis.</p>
2021-01-27 | MTBLS201 | MetaboLights
Project description:Mechanisms related to the development of cassava storage roots and starch accumulation remain largely unknown. To evaluate genome-wide expression patterns during cassava tuberization, a 60-mer oligonucleotide microarray representing 20,840 cassava genes was designed to identify differentially expressed transcripts in fibrous root, developing storage root and mature storage root. Using a random variance model and the traditional two-fold change method for statistical analysis, 912 and 3386 differentially expressed genes were identified related to the three different phases. Among 25 significant pathways identified, glycolysis/gluconeogenesis was the most important pathway signature due to its effects on other pathways. Rate-limiting enzymes were identified from each individual pathway, such as pectinesterase, enolase, L-lactate dehydrogenase and aldehyde dehydrogenase in glycolysis/gluconeogenesis, and ADP-glucose pyrophosphorylase, starch branching enzyme and glucan phosphorylase in sucrose and starch metabolism. This study revealed that dynamic changes in at least 16% of the transcriptome, including hundreds of transcription factors, oxidoreductases/transferases/hydrolases, hormone-related genes, and effectors of homeostasis, all of which highlight the complexity of this biological process. The reliability of differentially expressed genes in microarray analysis was further verified by quantitative real-time RT-PCR. The genome-wide transcription analysis facilitates our understanding of the formation of the storage root and deciphers key genes for further cassava improvement. Fibrous roots (FR), developing storage roots (DR) and mature storage roots (MR) were collected for RNA extractions from three independent healthy 4 month-old cassava (cultivar TMS60444) plants in the field .Two RNA samples extracted from stored storage root slices were used as technical repeats (TR) for quality control.
2011-05-13 | E-GEOD-25813 | biostudies-arrayexpress