Project description:This study use different ice recrystalization inhibitors (IRIs) for better storing live microbiota. We evaluated whether the addition of IRIs can improve the cultivibility of microbiome and maintain their resposnes to prebiotic kestose. Frozen or fresh microbiota were cultured with or without kestose for 24 hours, and microbiota samples were collected for metaproteomics analysis.
Project description:We explore whether a low-energy diet intervention for Metabolic dysfunction-associated steatohepatitis (MASH) improves liver disease by means of modulating the gut microbiome. 16 individuals were given a low-energy diet (880 kcal, consisting of bars, soups, and shakes) for 12 weeks, followed by a stepped re-introduction to whole for an additional 12 weeks. Stool samples were obtained at 0, 12, and 24 weeks for microbiome analysis. Fecal microbiome were measured using 16S rRNA gene sequencing. Positive control (Zymo DNA standard D6305) and negative control (PBS extraction) were included in the sequencing. We found that low-energy diet improved MASH disease without lasting alterations to the gut microbiome.
Project description:The gut microbiome is significantly altered in inflammatory bowel diseases, but the basis of these changes is not well understood. We have combined metagenomic and metatranscriptomic profiling of the gut microbiome to assess changes to both bacterial community structure and transcriptional activity in a mouse model of colitis. Gene families involved in microbial resistance to oxidative stress, including Dps/ferritin, Fe-dependent peroxidase and glutathione S-transferase, were transcriptionally up-regulated in colitis, implicating a role for increased oxygen tension in gut microbiota modulation. Transcriptional profiling of the host gut tissue and host RNA in the gut lumen revealed a marked increase in the transcription of genes with an activated macrophage and granulocyte signature, suggesting the involvement of these cell types in influencing microbial gene expression. Down-regulation of host glycosylation genes further supports a role for inflammation-driven changes to the gut niche that may impact the microbiome. We propose that members of the bacterial community react to inflammation-associated increased oxygen tension by inducing genes involved in oxidative stress resistance. Furthermore, correlated transcriptional responses between host glycosylation and bacterial glycan utilisation support a role for altered usage of host-derived carbohydrates in colitis. Complementary transcription profiling data from the mouse hosts have also been deposited at ArrayExpress under accession number E-MTAB-3590 ( http://www.ebi.ac.uk/arrayexpress/experiments/E-MTAB-3590/ ).
Project description:Background: The halophyte Mesembryanthemum crystallinum (ice plant) is a model for studying salt tolerance. The morphology, physiology, metabolism, and gene expression of ice plant have been studied for over 40 years. Although the complete genome sequence has not been revealed, large-scale analyses of gene expression profiling have drawn an outline of salt tolerance in ice plant. Despite ample information in the transcriptome, miRNA information has not been documented. Results: We examined responses to a sudden increase in salinity in ice plant seedlings. Using a fluorescent dye to detect Na+, we found that ice plant roots respond to an increased flux of Na+ by either secreting or storing Na+ in specialized cells. High-throughput sequencing was used to identify small RNA profiles in three-day-old seedlings treated with or without 200 mM NaCl. Totally 132 conserved miRNAs belonging to 22 families were found. The hairpin precursor of 19 conserved mcr-miRNAs and 12 novel mcr-miRNAs were identified. Target genes are involved in a broad range of biological processes: transcription factors that regulate growth and development, enzymes that catalyze miRNA biogenesis for the most conserved mcr-miRNA, and proteins that are involved in ion homeostasis and drought-stress responses for some novel mcr-miRNAs. After 6 h of salt stress, the expressions of most mcr-miRNAs were down-regulated, whereas the expressions of their corresponding target genes were up-regulated. Analyses of the functions of target genes revealed that cellular processes, including growth and development, metabolism, and ion transport activity were up-regulated in roots under salt stress. Conclusions: Analyses of small RNA profile of ice plant seedlings identified many conserved miRNA families and several novel miRNAs. The expression of ten conserved miRNAs and three novel miRNAs were reciprocally correlated to predicted targets hourly after salt stress. Based on the expression pattern of miRNA and target genes in combination with the observation of Na+ distribution, we suggest that ice plant roots respond effectively to increased salinity by using Na+ as an osmoticum for cell expansion and guard cell opening. Excessive Na+ could either be secreted through root epidermis or stored in specialized leaf epidermal cells. These responses are partially regulated at the miRNA-mediated post-transcriptional level.