Project description:In recent years, the gut microbiota and derived metabolites have emerged as relevant players in modulating several brain functions, including energy balance control. This form of distant communication mirrors that of metabolic hormones (e.g., leptin, ghrelin), that convey information about the organism's energy status by exerting effects on diverse brain regions including the master homeostatic centre the hypothalamus. However, whether the hypothalamus is also able to influence gut microbiota composition remains enigmatic. Here, we present a proof-of-concept study designed to unravel this challenging question. To this aim, we employed chemogenetics (to selectively activate or inhibit the activity of hypothalamic POMC or AgRP neurons) or administered leptin or ghrelin centrally to mice. Subsequently, we conducted microbiota composition analysis throughout the gut using 16S rRNA gene sequencing. Our results showed that these brain interventions significantly changed the gut microbiota in an anatomical and short-term (2-4h) fashion. Transcriptomic analysis indicated that these changes were associated with the reconfiguration of neuronal and synaptic pathways in the duodenum concomitant with increased sympathetic tone. Interestingly, diet-induced obesity attenuated brain-mediated changes induced by leptin in gut microbiota communities and sympathetic activation. Our findings reveal a novel and unanticipated brain-to-gut axis that acutely attunes microbiota composition at fast timescales, with potential implications for meal-to-meal adjustments and systemic energy balance control.
Project description:The gut microbiota impacts many aspects of host biology including immune function. One hypothesis is that microbial communities induce epigenetic changes with accompanying alterations in chromatin accessibility, providing a mechanism that allows a community to have sustained host effects even in the face of its structural or functional variation. We used ATAC-seq to define chromatin accessibility in predicted enhancer regions of intestinal αβ+ and γδ+ intraepithelial lymphocytes (IELs) purified from germ-free mice, their conventionally-raised (CONV-R) counterparts, and mice reared GF and then colonized with a CONV-R gut microbiota at the end of the suckling-weaning transition. Characterizing genes adjacent to traditional enhancers and super-enhancers revealed signaling networks, metabolic pathways, and enhancer-associated transcription factors affected by the microbiota. Our results support the notion that epigenetic modifications help define microbial community-affiliated functional features of host immune cell lineages.
2016-11-28 | GSE89646 | GEO
Project description:Adipokines influence on suckling rat GALT and microbiota
Project description:This study in rats was designed to investigate whether whole rhye (WR) can influence the metabolism of n-3 and n-6 long-chain fatty acids (LCFA) and gut microbiota composition. For 12 weeks, rats were fed a diet containing either 50% WR or 50% refined rye (RR). Total bacterial DNA was extracted from fecal and cecal samples (n=5 per group). 16S PCR amplification was performed to assess the microbial diversity at the family level using the HuGChip. Amplified DNA was purified and labelled with either Cy3 or Cy5 dye and hybridized on the microarray.
Project description:This study in rats was designed to investigate whether whole rhye (WR) can influence the metabolism of n-3 and n-6 long-chain fatty acids (LCFA) and gut microbiota composition. For 12 weeks, rats were fed a diet containing either 50% WR or 50% refined rye (RR). Total bacterial DNA was extracted from fecal and cecal samples (n=5 per group). 16S PCR amplification was performed to assess the microbial diversity at the family level using the HuGChip. Amplified DNA was purified and labelled with either Cy3 or Cy5 dye and hybridized on the microarray. A 15 chip study was realized, each corresponding to hybridization with 250ng of labelled 16S rRNA gene amplicons from either mice fecal and cecal samples. Each probe (4441) was synthetized in three replicates.
Project description:Chronic acid suppression by proton pump inhibitor (PPI) has been hypothesized to alter the gut microbiota via a change in intestinal pH. To evaluate the changes in gut microbiota composition by long-term PPI treatment. Twenty-four week old F344 rats were fed with (n = 5) or without (n = 6) lansoprazole (PPI) for 50 weeks. Then, profiles of luminal microbiota in the terminal ileum were analyzed. Pyrosequencing for 16S rRNA gene was performed by genome sequencer FLX (454 Life Sciences/Roche) and analyzed by metagenomic bioinformatics.
Project description:High protein diet alter gut microbiota composition and activity. The objective of this study is to determine the consequences of a high protein diet for the colonic epithelium in rats.
Project description:Rationale: Recent studies suggest a potential link between gut bacterial microbiota dysbiosis and PAH, but the exact role of gut microbial communities, including bacteria, archaea, and fungi, in PAH remains unclear. Objectives: To investigate the role of gut microbiota dysbiosis in idiopathic pulmonary arterial hypertension (IPAH) and to assess the therapeutic potential of fecal microbiota transplantation (FMT) in modulating PAH progression. Methods: Using shotgun metagenomics, we analyzed gut microbial communities in IPAH patients and healthy controls. FMT was performed to transfer gut microbiota from IPAH patients or MCT-PAH rats to normal rats and from healthy rats to MCT-PAH rats. Hemodynamic measurements, echocardiography, histological examination, metabolomic and RNA-seq analysis were conducted to evaluate the effects of FMT on PAH phenotypes. Measurements and Main Results: Gut microbiota analysis revealed significant alterations in the bacterial, archaeal, and fungal communities in IPAH patients compared to healthy controls. FMT from IPAH patients induced PAH phenotypes in recipient rats. Conversely, FMT from healthy rats to IPAH rats significantly ameliorated PAH symptoms, restored gut microbiota composition, and normalized serum metabolite profiles. Specific microbial species were identified with high diagnostic potential for IPAH, improving predictive performance beyond individual or combined microbial communities. Conclusions: This study establishes a causal link between gut microbiota dysbiosis and IPAH and demonstrates the therapeutic potential of FMT in reversing PAH phenotypes. The findings highlight the critical role of bacterial, archaeal, and fungal communities in PAH pathogenesis and suggest that modulation of the gut microbiome could be a promising treatment strategy for PAH.
Project description:This study aims to identify genome-wide placental DNA differential methylation positions (DMPs) in fetal overgrowth and the associations with fetal growth factors, leptin and adiponectin. In the Shanghai Birth Cohort, we studied 30 pairs of placentals of large-for-gestational-age (LGA, birth weight>90th percentile, an indicator of fetal overgrowth) and optimal-for-gestational-age (OGA, 25th-75th percentiles, control) newborns matched by sex and gestational age. Placental DNA methylations were measured by the Illumina Infinium Human Methylation-EPIC BeadChip. Cord blood insulin, C-peptide, proinsulin, IGF-1, IGF-2, leptin and adiponectin concentrations were measured. We identified 543 DMPs (397 hypermethylated, 146 hypomethylated) comparing LGA vs. OGA at false discovery rate <5% and absolute methylation difference >0.05 adjusting for placental cell type heterogeneity, maternal age, pre-pregnancy BMI and HbA1c levels during pregnancy. We validated a hyper-methylated gene - cadherin 13 (CDH13) reported in a previous epigenome-wide association study, and validated a newly discovered differentially (hyper-)methylated gene -visual system homeobox 1 (VSX1) in an independent pyrosequencing study sample (47 LGA-control pairs). Pathway analysis did not detect any statistically significant pathway correcting for multiple tests. Adiponectin in cord blood was correlated with its gene methylation in the placenta, while other observed biomarkers were not. Fetal overgrowth was associated with a large number of altered placental gene DNA methylations. The study provides robust evidence suggesting that placental CDH13 and VSX1 genes are hyper-methylated in LGA. Placental gene methylation was correlated with cord blood biomarker for adiponectin, but not for leptin and fetal growth factors.
Project description:Obesity is a leading cause of primary hypertension in children, and a high-fat intake and the gut microbiota may be involved in the pathogenesis of obesity-related hypertension (OrHTN), but the underlying mechanisms are not fully understood. Here, we show that high-fat diet (HFD) feeding alters the gut microbiota composition in OrHTN rats, resulting in a reduced abundance of the butyrate-producing bacteria Ruminococcus and a subsequent decrease in plasma butyrate levels. Histone 3 lysine 9 butyrylation (H3K9bu) levels decreased in the kidneys of OrHTN rats, which downregulates the expression of the hypertension-related MAS1 gene. Furthermore, sodium butyrate affected H3K9bu modification levels in a concentration-dependent manner, with decreased H3K9bu and downregulated MAS1 expression at low concentrations in human proximal tubular epithelial cells. Our results suggest that a HFD contributes to the development of OrHTN by altering the gut microbiota and its metabolites, leading to the downregulation of H3K9bu and hypertension-related gene expression.