Project description:Irritable Bowel Syndrome (IBS) is a disorder of the gut-brain axis, characterized by altered gut function and frequent psychiatric co-morbidity. Although altered intestinal microbiome profiles have been documented, their relevance to the clinical expression of IBS is unknown. To evaluate a functional role of the microbiota, we colonized germ-free mice with fecal microbiota from healthy controls or IBS patients with accompanying anxiety, and monitored gut function and behavior. Mouse microbiota profiles clustered according to their human donors. Despite having taxonomically similar composition as controls, mice with IBS microbiota had distinct serum metabolomic profiles related to neuro- and immunomodulation. Mice with IBS, but not control microbiota, exhibited faster gastrointestinal transit, intestinal barrier dysfunction, innate immune activation and anxiety-like behavior. These results support the notion that the microbiota contributes to both intestinal and behavioral manifestations of IBS and rationalize the use of microbiota-directed therapies in ameliorating IBS.
Project description:Gut microbiome research is rapidly moving towards the functional characterization of the microbiota by means of shotgun meta-omics. Here, we selected a cohort of healthy subjects from an indigenous and monitored Sardinian population to analyze their gut microbiota using both shotgun metagenomics and shotgun metaproteomics. We found a considerable divergence between genetic potential and functional activity of the human healthy gut microbiota, in spite of a quite comparable taxonomic structure revealed by the two approaches. Investigation of inter-individual variability of taxonomic features revealed Bacteroides and Akkermansia as remarkably conserved and variable in abundance within the population, respectively. Firmicutes-driven butyrogenesis (mainly due to Faecalibacterium spp.) was shown to be the functional activity with the higher expression rate and the lower inter-individual variability in the study cohort, highlighting the key importance of the biosynthesis of this microbial by-product for the gut homeostasis. The taxon-specific contribution to functional activities and metabolic tasks was also examined, giving insights into the peculiar role of several gut microbiota members in carbohydrate metabolism (including polysaccharide degradation, glycan transport, glycolysis and short-chain fatty acid production). In conclusion, our results provide useful indications regarding the main functions actively exerted by the gut microbiota members of a healthy human cohort, and support metaproteomics as a valuable approach to investigate the functional role of the gut microbiota in health and disease.
Project description:Major depressive disorder is caused by gene-environment interactions and the gut microbiota plays a pivotal role in the development of depression. However, the mechanisms by which the gut microbiota modulates depression remain elusive. Herein, we detected the differentially expressed hippocampal long non-coding RNAs (lncRNAs), messenger RNAs (mRNAs) and microRNAs (miRNAs) between mice inoculated with gut microbiota from major depressive disorder patients or healthy controls, to identify the effects of gut microbiota-dysbiosis on gene regulation patterns at the transcriptome level. We also performed functional analysis to explore the microbial-regulated pathological mechanisms of depression. Two hundred mRNAs, 358 lncRNAs and 4 miRNAs were differentially expressed between the two groups. Functional analysis of these differentially expressed mRNAs indicated dysregulated inflammatory response to be the primary pathological change. Intersecting the differentially expressed mRNAs with targets of differentially expressed miRNAs identified 47 intersected mRNAs, which were mainly related to neurodevelopment. Additionally, we constructed a microbial-regulated lncRNA-miRNA-mRNA network based on RNA-RNA interactions. According to the competitive endogenous RNA hypothesis, two neurodevelopmental ceRNA sub-networks implicating in depression were identified. This study provides new understanding of the pathogenesis of depression induced by gut microbiota-dysbiosis and may act as a theoretical basis for the development of gut microbiota-based antidepressants.
Project description:Major depressive disorder is caused by gene-environment interactions and the gut microbiota plays a pivotal role in the development of depression. However, the mechanisms by which the gut microbiota modulates depression remain elusive. Herein, we detected the differentially expressed hippocampal long non-coding RNAs (lncRNAs), messenger RNAs (mRNAs) and microRNAs (miRNAs) between mice inoculated with gut microbiota from major depressive disorder patients or healthy controls, to identify the effects of gut microbiota-dysbiosis on gene regulation patterns at the transcriptome level. We also performed functional analysis to explore the microbial-regulated pathological mechanisms of depression. Two hundred mRNAs, 358 lncRNAs and 4 miRNAs were differentially expressed between the two groups. Functional analysis of these differentially expressed mRNAs indicated dysregulated inflammatory response to be the primary pathological change. Intersecting the differentially expressed mRNAs with targets of differentially expressed miRNAs identified 47 intersected mRNAs, which were mainly related to neurodevelopment. Additionally, we constructed a microbial-regulated lncRNA-miRNA-mRNA network based on RNA-RNA interactions. According to the competitive endogenous RNA hypothesis, two neurodevelopmental ceRNA sub-networks implicating in depression were identified. This study provides new understanding of the pathogenesis of depression induced by gut microbiota-dysbiosis and may act as a theoretical basis for the development of gut microbiota-based antidepressants.
Project description:This study aimed to explain the mechanism of ZZCD in treating anxious depression from the perspective of the brain-gut axis by constructing multiple connections between the nucleus accumbent (NAc) and intestinal flora in anxiety-depressed mice.
Project description:We have previously demonstrated that the gut microbiota can play a role in the pathogenesis of conditions associated with exposure to environmental pollutants. It is well accepted that diets high in fermentable fibers such as inulin can beneficially modulate the gut microbiota and lessen the severity of pro-inflammatory diseases. Therefore, we aimed to test the hypothesis that hyperlipidemic mice fed a diet enriched with inulin would be protected from the pro-inflammatory toxic effects of PCB 126.
Project description:Major depressive disorder (MDD) is a leading cause of disability around the world and contributes greatly to the global burden of disease. Mounting evidence suggests that gut microbiota dysbiosis may be involved in the pathophysiology of MDD through the microbiota–gut–brain axis. Recent research suggests that epigenetic modifications might relate to depression. However, our knowledge of the role of epigenetics in host–microbe interactions remains limited. In the present study, we used a combination of affinity enrichment and high-resolution liquid chromatography tandem mass spectrometry analysis to identify hippocampal acetylated proteins in germ-free(GF) and specific pathogen-free(SPF) mice. In total, 986 lysine acetylation sites in 543 proteins were identified, of which 747 sites in 427 proteins were quantified. Motif analysis identified several conserved sequences surrounding the acetylation sites, including D*Kac, DKac, KacY, KacD, and D**Kac. Gene ontology annotations revealed that these differentially expressed acetylated proteins were involved in multiple biological functions and mainly located in mitochondria. In addition, pathway enrichment analysis showed that oxidative phosphorylation and the tricarboxylic acid (TCA) cycle II (eukaryotic), both of which are exclusively localized to the mitochondria, were the primarily disturbed functions. Taken together, this study indicates that lysine acetylation changes may play a pivotal role in the mitochondrial dysfunction by which gut microbiota regulate brain function and behavioral phenotypes.
Project description:Intracerebral hemorrhage (ICH) induces alterations in the gut microbiota composition, significantly impacting neuroinflammation post-ICH. However, the impact of gut microbiota absence on neuroinflammation following ICH-induced brain injury remain unexplored. Here, we observed that the gut microbiota absence was associated with reduced neuroinflammation, alleviated neurological dysfunction, and mitigated gut barrier dysfunction post-ICH. In contrast, recolonization of microbiota from ICH-induced SPF mice by transplantation of fecal microbiota (FMT) exacerbated brain injury and gut impairment post-ICH. Additionally, microglia with transcriptional changes mediated the protective effects of gut microbiota absence on brain injury, with Apoe emerging as a hub gene. Subsequently, Apoe deficiency in peri-hematomal microglia was associated with improved brain injury. Finally, we revealed that gut microbiota influence brain injury and gut impairment via gut-derived short-chain fatty acids (SCFA).
Project description:Background: The long-term high-fat, high-sugar diet exacerbates type 2 diabetes mellitus (T2DM)-related cognitive impairments. The negative impact of poor dietary patterns on brain development and neurological function may be related to gut microbiota disturbance. The role of phlorizin in mitigating glucose and lipid metabolism disorders is well documented. However, the protective effect of phlorizin on diabetes-related cognitive dysfunction is unclear. Therefore, the present study aimed to investigate the effect of dietary supplementation of phlorizin on high-fat and high-fructose diet (HFFD)-induced cognitive dysfunction and evaluate the crucial role of the microbiota-gut-brain axis. Results: Dietary supplementation of phlorizin for 14 weeks effectively prevented glucolipid metabolism disorder, spatial learning impairment, and memory impairment in HFFD mice. In addition, phlorizin improved the HFFD-induced decrease in synaptic plasticity, neuroinflammation, and excessive activation of microglia in the hippocampus. Transcriptomics analysis shows that the protective effect of phlorizin on cognitive impairment was associated with increased expression of neurotransmitters and synapse-related genes in the hippocampus. Phlorizin treatment alleviated colon microbiota disturbance, mainly manifested by an increase in gut microbiota diversity and the abundance of short-chain fatty acid (SCFA)-producing bacteria. The level of microbial metabolites, including SCFA, inosine 5'-monophosphate (IMP), and D (-)-beta-hydroxybutyric acid (BHB) were also significantly increased after phlorizin treatment. Moreover, integrating multiomics analysis observed tight connections between phlorizin-regulated genes, microbiota, and metabolites. Furthermore, removal of the gut microbiota via antibiotics treatment diminished the protective effect of phlorizin against HFFD-induced cognitive impairment, underscoring the critical role of the gut microbiota in mediating cognitive behavior. Importantly, supplementation with SCFA and BHB alone mimicked the regulatory effects of phlorizin on cognitive function. Conclusions: These results indicate that gut microbiota and their metabolites mediate the ameliorative effect of phlorizin on HFFD-induced cognitive impairment. Therefore, phlorizin can be used as an easy-to-implement nutritional therapy to prevent and alleviate metabolism-related neurodegenerative diseases by targeting the regulation of the microbiome-gut-brain axis.
Project description:Gut microbiota plays an important role during early development via bidirectional gut- brain signaling. We aimed to explore the potential link between gut microbiota/gut derived metabolites and sympathoadrenal stress responsivity