Project description:Eriocitrin, found in lemon fruit, has shown a wide range of biological properties. Herein, to evaluate the intestinal metabolic profile of eriocitrin in colon, the flavonoids in mice colon contents were identified by ultra performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS), and a total of 136 flavonoids were found, including eriocitrin and its six metabolites (eriodictyol, homoeriodictyol, hesperetin, eriodictyol-3'-O-glucoside, hesperetin-7-O-glucoside and eriodictyol-7-O-(6''-O-galloyl) glucoside). Mice colon contents were used for 16S rDNA gene sequencing and gas chromatography-mass (GC-MS). Resultu showed that eriocitrin significantly alters the beta diversity of the gut microbiota, the probiotics such as Lachnospiraceae_UCG_006 were significantly enriched, and the production of butyrate, valerate and hexanoate in the colon pool of short-chain fatty acids (SCFAs) were significant increased. The spearman's association analysis performed some intestinal bacteria may be involved in the metabolism of eriocitrin. Collectively, our results preliminarily suggesting the metabolism of eriocitrin in the gut, demonstrate alterations of eriocitrin on gut microbiota, which warrants further investigation to determine its potential use in food and biomedical applications.
Project description:To characterize the effect of microbiota on global gene expression in the distal small intestine during postnatal gut development we employed mouse models with experimental colonization by intestinal microbiota. Using microarray analysis to assess global gene expression in ileal mucosa at the critical stage of intestinal development /maturation associated with weaning, and asking how expression is affected by microbial colonization In the study presented here, preweaned and postweaned GF, SPF mouse small intestinal total RNAs were used. Also, 3-week-old gnotobiotic mouse as well as GF mouse small intestinal RNAs were used.
Project description:Opioid use is associated with worse outcome in HIV-infected patients. The exacerbated disease progression by opioids is mainly driven by increased epithelial damage and less regenerative response. The present study investigates how opioids potentiate HIV disease progression by impairing intestinal epithelial self-repair. Abnormal intestinal morphology and reduced epithelial proliferation were observed in HIV-infected humanized mice, which were exposed to opioids. For this study, we had 4 groups of BLT humanized mice- (A) Untreated, (B) Morphine treated, (C) HIV infected and (D) HIV infected + Morphine treated. HIV infection was done for 4 weeks and Morphine treatment was done for 7 days. Morphine treatment was done via subcutaneous implantation of slow-release morphine pellet in individual mouse in the appropriate groups. In other groups, a matching Placebo pellet was implanted.
Project description:Extracellular membrane vesicles (MVs) released by gut microbiota are key players in the communication with the host. Next-generation sequencing of small RNAs was used to quantify miRNA expression in monocyte-derived dendritic cells after 24 h-stimulation with MVs isolated from two E. coli intestinal isolates, the probiotic E. coli strain Nissle 1917 (EcN) and the commensal ECOR12. Analysis revealed miRNAs differentially expressed in response to MVs compared to immature control dendritic cells (log2fold-change > 0.7 and padj < 0.001). A common set of miRNAs was modulated by MVs from both strains (46 downregulated, 75 upregulated). In addition, these vesicles elicited differential expression of specific miRNAs depending on the producer strain (26 downregulated and 23 upregulated by EcN; 48 downregulated and 49 upregulated by ECOR12).
Project description:The intestinal epithelium is protected by a mucus layer infused with antimicrobial proteins, forming a physical and chemical barrier that limits microbial access to host tissue. Mucus barrier assembly is energetically costly, yet how production of its constituent proteins is matched to demand remains unclear. Here, we show that the microbiota regulates gut barrier immunity by enhancing translation of select defense proteins, including mucin 2 and lysozyme. This occurs via induction of histone deacetylase 5 (HDAC5) in secretory epithelial cells. HDAC5 deacetylates 14-3-3, enabling it to sequester Raptor, a component of mTORC1. This releases mTOR and activates downstream signaling that promotes translation of barrier defense proteins. Our findings reveal a mechanism by which the microbiota shapes barrier immunity through translational control.
Project description:Cognitive impairment (CI) is a prevalent neurological condition characterized deficient attention, causal reasoning, learning and/or memory. Many genetic and environmental factors increase risk for CI, and the gut microbiome is increasingly implicated. However, the identity of gut microbes associated with CI risk, their effects on CI, and their mechanisms of action remain unclear. Here we examine the gut microbiome in response to restricted diet and intermittent hypoxia, known environmental risk factors for CI. Modeling the environmental factors together in mice potentiates CI and alters the gut microbiota. Depleting the microbiome by antibiotic treatment or germ-free rearing prevents the adverse effects of environmental risk on CI, whereas transplantation of the risk-associated microbiome into naïve mice confers CI. Parallel sequencing and gnotobiotic approaches identify the pathobiont Bilophila wadsworthia as enriched by the environmental risk factors for CI and as sufficient to induce CI. Consistent with CI-related behavioral abnormalities, B. wadsworthia and the risk-associated microbiome disrupt hippocampal activity, neurogenesis and gene expression. The CI induced by B. wadsworthia and by environmental risk factors is associated with microbiome-dependent increases in intestinal IFNy-producing Th1 cells. Inhibiting Th1 cells abrogates the adverse effects of both B. wadsworthia and environmental risk factors on CI. Together, these findings identify select gut bacteria that contribute to environmental risk for CI in mice by promoting inflammation and hippocampal dysfunction.
Project description:Inappropriate cross talk between mammals and their gut microbiota may trigger intestinal inflammation and drive extra-intestinal immune-mediated diseases. Studies with germ-free or gnotobiotic animals represent the gold standard for research on bacterial-host interaction but they are not readily accessible to the wide scientific community. We aimed at refining a protocol that in a robust manner would deplete murine intestinal microbiota and prove to have significant biologic validity. Previously published protocols for depleting mice of their intestinal microbiota by administering broad-spectrum antibiotics in drinking water were difficult to reproduce. We show that twice daily delivery of antibiotics by gavage depleted mice of their cultivable fecal microbiota and reduced the fecal bacterial DNA load by approximately 400 fold while ensuring the animals’ health. Mice subjected to the protocol for 17 days displayed enlarged ceca, reduced Peyer’s patches and small spleens. Antibiotic treatment significantly reduced the expression of antimicrobial factors and altered the expression of 517 genes in total in the colonic epithelium. Genes involved in cell cycle were significantly altered concomitant with reduced epithelial proliferative activity in situ assessed by Ki-67 expression, suggesting that commensal microbiota drives cellular proliferation in colonic epithelium. We present a robust protocol for depleting mice of their cultivatable intestinal microbiota with antibiotics by gavage and show that the biological effect of this depletion is phenotypic characteristics and epithelial gene expression profile similar to those of germ-free mice. Comparison of genome-wide gene expression of colon intestinal epithelial cells from mice subjected to microbiota depletion protocol against to control mice.
Project description:Intestinal Foxp3+ regulatory T cell (Treg) subsets are crucial players in tolerance to microbiota-derived and food-borne antigens, and compelling evidence suggests that the intestinal microbiota modulates their generation, functional specialization, and maintenance. Selected bacterial species and microbiota-derived metabolites, such as short-chain fatty acids (SCFAs), have been reported to promote Treg homeostasis in the intestinal lamina propria. Furthermore, gut-draining mesenteric lymph nodes (mLNs) are particularly efficient sites for the generation of peripherally induced Tregs (pTregs). Despite this knowledge, the direct role of the microbiota and their metabolites in the early stages of pTreg induction within mLNs is not fully elucidated. Here, using an adoptive transfer-based pTreg induction system, we demonstrate that neither transfer of a dysbiotic microbiota nor dietary SCFA supplementation modulated the pTreg induction capacity of mLNs. Even mice housed under germ-free (GF) conditions displayed equivalent pTreg induction within mLNs. Further molecular characterization of these de novo induced pTregs from mLNs by dissection of their transcriptomes and accessible chromatin regions revealed that the microbiota indeed has a limited impact and does not contribute to the initialization of the Treg-specific epigenetic landscape. Overall, our data suggest that the microbiota is dispensable for the early stages of pTreg induction within mLNs.
Project description:Aim: The experiment was performed to investigate the effects of intestinal microbial colonization on the hepatic transcriptome of mice.
Project description:The effect of oral microbiota on the intestinal microbiota has garnered growing attention as a mechanism linking periodontal diseases to systemic diseases. However, the salivary microbiota is diverse and comprises numerous bacteria with a largely similar composition in healthy individuals and periodontitis patients. Thus, the systemic effects of small differences in the oral microbiota are unclear. In this study, we explored how health-associated and periodontitis-associated salivary microbiota differently colonized the intestine and their subsequent systemic effects by analyzing the hepatic gene expression and serum metabolomic profiles. The salivary microbiota was collected from a healthy individual and a periodontitis patient and gavaged into C57BL/6NJcl[GF] mice. Samples were collected five weeks after administration. Gut microbial communities were analyzed by 16S ribosomal RNA gene sequencing. Hepatic gene expression profiles were analyzed using a DNA microarray and quantitative polymerase chain reaction. Serum metabolites were analyzed by capillary electrophoresis time-of-flight mass spectrometry. The gut microbial composition at the genus level was significantly different between periodontitis-associated microbiota-administered (PAO) and health-associated oral microbiota-administered (HAO) mice. The hepatic gene expression profile demonstrated a distinct pattern between the two groups, with higher expression of Neat1, Mt1, Mt2, and Spindlin1, which are involved in lipid and glucose metabolism. Disease-associated metabolites such as 2-hydroxyisobutyric acid and hydroxybenzoic acid were elevated in PAO mice. These metabolites were significantly correlated with Bifidobacterium, Atomobium, Campylobacter, and Haemophilus, which are characteristic taxa in PAO mice. Conversely, health-associated oral microbiota were associated with higher levels of beneficial serum metabolites in HAO mice. The multi-omics approach used in this study revealed that periodontitis-associated oral microbiota is associated with the induction of disease phenotype when they colonized the gut of germ-free mice.