Project description:Gut microbiota dysbiosis characterizes systemic metabolic alteration, yet its causality is debated. To address this issue, we transplanted antibiotic-free conventional wild-type mice with either dysbiotic (“obese”) or eubiotic (“lean”) gut microbiota and fed them either a NC or a 72%HFD. We report that, on NC, obese gut microbiota transplantation reduces hepatic gluconeogenesis with decreased hepatic PEPCK activity, compared to non-transplanted mice. Of note, this phenotype is blunted in conventional NOD2KO mice. By contrast, lean microbiota transplantation did not affect hepatic gluconeogenesis. In addition, obese microbiota transplantation changed both gut microbiota and microbiome of recipient mice. Interestingly, hepatic gluconeogenesis, PEPCK and G6Pase activity were reduced even once mice transplanted with the obese gut microbiota were fed a 72%HFD, together with reduced fed glycaemia and adiposity compared to non-transplanted mice. Notably, changes in gut microbiota and microbiome induced by the transplantation were still detectable on 72%HFD. Finally, we report that obese gut microbiota transplantation may impact on hepatic metabolism and even prevent HFD-increased hepatic gluconeogenesis. Our findings may provide a new vision of gut microbiota dysbiosis, useful for a better understanding of the aetiology of metabolic diseases. all livers are from NC-fed mice only.
Project description:Microbial RNAseq analysis of cecal and fecal samples collected from mice colonized with the microbiota of human twins discordant for obesity. Samples were colleted at the time of sacrifice, or 15 days after colonization from mice gavaged with uncultured or cultured fecal microbiota from the lean twins or their obese co-twins. Samples were sequenced using Illumina HiSeq technology, with 101 paired end chemistry. Comparisson of microbial gene expression between the microbiota of lean and obese twins fed a Low fat, rich in plant polysaccharide diet.
Project description:Microarray analysis comparing gene expression profiles of primary cultured preadipocytes from non-diabetic lean vs non-diabetic obese Pima Indian subjects (a subset of the subjects from the adipocyte genechip project, GSE2508). Primary cultured abdominal subcutaneous preadipocytes from 14 lean (7 Males / 7 Females) and 14 obese (7M/7F) subjects were hybridized individually to Affymetrix oligonucleotide arrays HG-U133A and B.
Project description:Microarray analysis comparing gene expression profiles of adipocytes from non-diabetic lean vs non-diabetic obese Pima Indian subjects to identify differentially expressed adipocyte genes with obesity. RNA samples of isolated abdominal subcutaneous adipocytes from 20 lean (10 Males / 10 Females, aged 31±6 year, Body Mass Index 25±3 kg/m2 ) and 19 obese (9M/10F, 29±5y, 55±8 kg/m2 ) subjects were hybridized individually to Affymetrix oligonucleotide arrays HG-U95A, B, C, D, and E.
Project description:Gender bias and the role of sex hormones in autoimmune diseases are well established. In specific-pathogen free (SPF) non-obese diabetic (NOD) mice females have 1.3-4.4 times higher incidence of Type 1 diabetes (T1D). Germ-free (GF) mice lose the gender bias (female/male ratio 1.1-1.2). Gut microbiota differed in males and females, a trend reversed by male castration, confirming that androgens influence gut microbiota. Colonization of GF NOD mice with defined microbiota revealed that some but not all lineages overrepresented in male mice supported a gender bias in T1D, and protection did not correlate with androgen levels. However, hormone-supported selective microbial lineage variation may work as a positive feedback mechanism contributing to the sexual dimorphism of autoimmune diseases. Gene expression analysis suggested pathways involved in protection of males from T1D by microbiota. We compared gene expression patterns in the pancreatic lymph nodes (PLNs) between four groups of mice (two genders in SPF and GF conditions, respectively). PLNs were isolated from 9-10 week old GF and SPF male and female NOD mice with 3 mice in each group, for a total of 12 samples.
Project description:Distal gut bacteria play a pivotal role in the digestion of dietary polysaccharides by producing a large number of carbohydrate-active enzymes (CAZymes) that the host otherwise does not produce. We report here the design of a high density custom microarray that we used to spot non-redundant DNA probes for more than 6,500 genes encoding glycoside hydrolases and lyases selected from 174 reference genomes from distal gut bacteria. The custom microarray was tested and validated by the hybridization of bacterial DNA extracted from the stool samples of lean, obese and anorexic individuals. Our results suggest that a microarray-based study can detect genes from low-abundance bacteria better than metagenomic-based studies. A striking example was the finding that a gene encoding a GH6-family cellulase was present in all subjects examined, whereas metagenomic studies have consistently failed to detect this gene in both human and animal gut microbiomes. In addition, an examination of eight stool samples allowed the identification of a corresponding CAZome core containing 46 families of glycoside hydrolases and polysaccharide lyases, which suggests the functional stability of the gut microbiota despite large taxonomical variations between individuals. Fecal samples were collected from eight female subjects. Three were obese subjects of BMI kg m-2: 35, 46.8 and 51.3, respectively; age: 42, 21 and 65 years old, respectively. Three were anorexic women of BMI kg m-2: 9.8, 10 and 13.7, respectively; age: 19, 23 and 49 years old, respectively. Finally, two fecal samples from lean women of BMI kg m-2: 18.6 and 23.42 were analyzed.
Project description:The overall goal of this studyis to compare the transcription differences of epicardial adipose tissue between between lean and obese and Type 2 diabetic individuals
Project description:Gender bias and the role of sex hormones in autoimmune diseases are well established. In specific-pathogen free (SPF) non-obese diabetic (NOD) mice females have 1.3-4.4 times higher incidence of Type 1 diabetes (T1D). Germ-free (GF) mice lose the gender bias (female/male ratio 1.1-1.2). Gut microbiota differed in males and females, a trend reversed by male castration, confirming that androgens influence gut microbiota. Colonization of GF NOD mice with defined microbiota revealed that some but not all lineages overrepresented in male mice supported a gender bias in T1D, and protection did not correlate with androgen levels. However, hormone-supported selective microbial lineage variation may work as a positive feedback mechanism contributing to the sexual dimorphism of autoimmune diseases. Gene expression analysis suggested pathways involved in protection of males from T1D by microbiota.