Project description:We quantitatively examine inputs and outputs of the mouse gut microbiome, using isotope tracing. To determine nutrient preferences across bacteria, we traced into genus-specific bacterial protein sequences. By in vivo isotope tracer feeding, mapped the contribution of different dietary nutrients vs circulating nutrients contribution to different gut bacterial genera.
Project description:The human colon contains an extensively diverse microbial ecosystem and one of the most numerous communities of immune cells. Studies have highlighted dynamic crosstalk between immune cells and commensals. While studies have demonstrated increasing diversity of microbiota from stomach to stool, whether and how immune cell heterogeneity and microbiota diversity change across the colon is undefined. Furthermore, whether these changes are co-depended in the healthy colon is unknown. Here, tissue samples are collected from caecum, transverse colon, sigmoid colon and mLN of cadaveric donors by the Cambridge Biorepository of Translational Medicine (CBTM). We use single cell RNA sequencing (10X genomics) to assess the dynamics of immune cell populations across the colon and in matching lymph nodes. Associated microbiome 16S sequencing data is available.
Project description:The human colon contains an extensively diverse microbial ecosystem and one of the most numerous communities of immune cells. Studies have highlighted dynamic crosstalk between immune cells and commensals. While studies have demonstrated increasing diversity of microbiota from stomach to stool, whether and how immune cell heterogeneity and microbiota diversity change across the colon is undefined. Furthermore, whether these changes are co-depended in the healthy colon is unknown. Here, tissue samples are collected from caecum, transverse colon, sigmoid colon and mLN of cadaveric donors by the Cambridge Biorepository of Translational Medicine (CBTM). We use single cell RNA sequencing (10X genomics) to assess the dynamics of immune cell populations across the colon and in matching lymph nodes. Associated microbiome 16S sequencing data is available.
Project description:The human colon contains an extensively diverse microbial ecosystem and one of the most numerous communities of immune cells. Studies have highlighted dynamic crosstalk between immune cells and commensals. While studies have demonstrated increasing diversity of microbiota from stomach to stool, whether and how immune cell heterogeneity and microbiota diversity change across the colon is undefined. Furthermore, whether these changes are co-depended in the healthy colon is unknown. Here, tissue samples are collected from caecum, transverse colon, sigmoid colon and mLN of cadaveric donors by the Cambridge Biorepository of Translational Medicine (CBTM). We use single cell RNA sequencing (10X genomics) to assess the dynamics of immune cell populations across the colon and in matching lymph nodes. Associated microbiome 16S sequencing data is available.
Project description:The human colon contains an extensively diverse microbial ecosystem and one of the most numerous communities of immune cells. Studies have highlighted dynamic crosstalk between immune cells and commensals. While studies have demonstrated increasing diversity of microbiota from stomach to stool, whether and how immune cell heterogeneity and microbiota diversity change across the colon is undefined. Furthermore, whether these changes are co-depended in the healthy colon is unknown. Here, tissue samples are collected from caecum, transverse colon, sigmoid colon and mLN of cadaveric donors by the Cambridge Biorepository of Translational Medicine (CBTM). We use single cell RNA sequencing (10X genomics) to assess the dynamics of immune cell populations across the colon and in matching lymph nodes. Associated microbiome 16S sequencing data is available.
Project description:The human colon contains an extensively diverse microbial ecosystem and one of the most numerous communities of immune cells. Studies have highlighted dynamic crosstalk between immune cells and commensals. While studies have demonstrated increasing diversity of microbiota from stomach to stool, whether and how immune cell heterogeneity and microbiota diversity change across the colon is undefined. Furthermore, whether these changes are co-depended in the healthy colon is unknown. Here, tissue samples are collected from caecum, transverse colon, sigmoid colon and mLN of cadaveric donors by the Cambridge Biorepository of Translational Medicine (CBTM). We use single cell RNA sequencing (10X genomics) to assess the dynamics of immune cell populations across the colon and in matching lymph nodes. Associated microbiome 16S sequencing data is available.
Project description:Fire disturbances are becoming more common, more intense, and further-reaching across the globe, with consequences for ecosystem functioning. Importantly, fire can have strong effects on the soil microbiome, including community and functional changes after fire, but surprisingly little is known regarding the role of soil fire legacy in shaping responses to recent fire. To address this gap, we conducted a manipulative field experiment administering fire across 32 soils with varying fire legacies, including combinations of 1-7 historic fires and 1-33 years since most recent fire. We analyzed soil metatranscriptomes, determining for the first time how fire and fire legacy interactively affect metabolically-active soil taxa, the microbial regulation of important carbon (C), nitrogen (N) and phosphorus (P) cycling, expression of carbohydrate-cycling enzyme pathways, and functional gene co-expression networks. Experimental fire strongly downregulated fungal activity while upregulating many bacterial and archaeal phyla. Further, fire decreased soil capacity for microbial C and N cycling and P transport, and drastically rewired functional gene co-expression. Perhaps most importantly, we highlight a novel role of soil fire legacy in regulation of microbial C, N, and P responses to recent fire. We observed a greater number of functional genes responsive to the interactive effects of fire and fire legacy than those affected solely by recent fire, indicating that many functional genes respond to fire only under certain fire legacy contexts. Therefore, without incorporating fire legacy of soils, studies will miss important ways that fire shapes microbial roles in ecosystem functioning. Finally, we showed that fire caused significant downregulation of carbon metabolism and nutrient cycling genes in microbiomes under abnormal soil fire histories, producing a novel warning for the future: human manipulation of fire legacies, either indirectly through global change-induced fire intensification or directly through fire suppression, can negatively impact soil microbiome functional responses to new fires.
Project description:Desert microbial communities live in a pulsed ecosystem shaped by isolated and rare precipitation events. The Namib desert is one of the oldest continuously hyperarid ecosystems on Earth. In this study, surface microbial communities of open soils (without sheltering features like rocks, vegetation or biological soil crusts) are analysed. We designed an artificial rainfall experiment where a 7x7 (3.5 x 3.5 m) plot remained dry while an adjacent one received a 30 mm simulated rain. Samples were taken randomly in parallel from both plots at 10 min, 1 h, 3 h, 7 h, 24 h and 7 days after the watering moment. Duplicate libraries were generated from total (rRNA depleted) RNA and sequenced 2x150 bp in an Illumina Hiseq 4000 instrument.
Project description:Transcriptional profiling was utilized to define the biological pathways of gingival epithelial cells modulated by mono- and complex co-culture with oral commensal S. gordonii and pathogenic P. gingivalis. We used microarrays to detail the global programme of gene expression underlying infection and identified distinct classes of up- and down-regulated genes during this process. Experiment Overall Design: Gingival epithelial HIGK cells were sham infected (CTRL) and infected with either the oral commensal S. gordonii (Sg) or the pathogenic P. gingivalis (Pg) as well as co-cultured in mixed cultures of Sg and Pg (Sg+Pg). These samples were hybridized to Affymetrix microarrays. Understanding how host cells have adapted to commensals, and how barrier cells respond to limit their impact, provides a mechanistic biological basis of health in the mixed bacterial-human ecosystem of the oral cavity and provides insight on how the degree of complexity of a microbiome influences this balance.