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: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: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: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 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:Colorectal cancer is a leading cause of cancer-related deaths. Mutations in the innate immune receptor AIM2 are frequently identified in patients with colorectal cancer, but how AIM2 modulates colonic tumorigenesis is unknown. Here, we found that Aim2-deficient mice were hypersusceptible to colonic tumor development. Production of inflammasome-associated cytokines and other inflammatory mediators were largely intact in Aim2-deficient mice, however, intestinal stem cells were prone to uncontrolled proliferation. Aberrant Wnt signaling expanded a population of tumor-initiating stem cells in the absence of AIM2. Susceptibility of Aim2-deficient mice to colorectal tumorigenesis was enhanced by a dysbiotic gut microbiota, which was reduced by reciprocal exchange of gut microbiota with wild-type healthy mice. These findings uncover a synergy between a specific host genetic factor and gut microbiota in determining the susceptibility to colorectal cancer. Therapeutic modulation of AIM2 expression and microbiota has the potential to prevent colorectal cancer. We used microarrays to compare the transcriptome Aim2 deficent mice to wild type mice in colon tumor and colitis samples. Here were 12 mice in total, 3 for each genotype and tissue combination.
Project description:Mardinoglu2015 - Tissue-specific genome-scale
metabolic network - Kidney cortex
This model is described in the article:
The gut microbiota modulates
host amino acid and glutathione metabolism in mice.
Mardinoglu A, Shoaie S, Bergentall
M, Ghaffari P, Zhang C, Larsson E, Bäckhed F, Nielsen
J.
Mol. Syst. Biol. 2015; 11(10):
834
Abstract:
The gut microbiota has been proposed as an environmental
factor that promotes the progression of metabolic diseases.
Here, we investigated how the gut microbiota modulates the
global metabolic differences in duodenum, jejunum, ileum,
colon, liver, and two white adipose tissue depots obtained from
conventionally raised (CONV-R) and germ-free (GF) mice using
gene expression data and tissue-specific genome-scale metabolic
models (GEMs). We created a generic mouse metabolic reaction
(MMR) GEM, reconstructed 28 tissue-specific GEMs based on
proteomics data, and manually curated GEMs for small intestine,
colon, liver, and adipose tissues. We used these functional
models to determine the global metabolic differences between
CONV-R and GF mice. Based on gene expression data, we found
that the gut microbiota affects the host amino acid (AA)
metabolism, which leads to modifications in glutathione
metabolism. To validate our predictions, we measured the level
of AAs and N-acetylated AAs in the hepatic portal vein of
CONV-R and GF mice. Finally, we simulated the metabolic
differences between the small intestine of the CONV-R and GF
mice accounting for the content of the diet and relative gene
expression differences. Our analyses revealed that the gut
microbiota influences host amino acid and glutathione
metabolism in mice.
This model is hosted on
BioModels Database
and identified by:
MODEL1509220012.
To cite BioModels Database, please use:
BioModels Database:
An enhanced, curated and annotated resource for published
quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
Project description:Mardinoglu2015 - Tissue-specific genome-scale
metabolic network - Liver
This model is described in the article:
The gut microbiota modulates
host amino acid and glutathione metabolism in mice.
Mardinoglu A, Shoaie S, Bergentall
M, Ghaffari P, Zhang C, Larsson E, Bäckhed F, Nielsen
J.
Mol. Syst. Biol. 2015; 11(10):
834
Abstract:
The gut microbiota has been proposed as an environmental
factor that promotes the progression of metabolic diseases.
Here, we investigated how the gut microbiota modulates the
global metabolic differences in duodenum, jejunum, ileum,
colon, liver, and two white adipose tissue depots obtained from
conventionally raised (CONV-R) and germ-free (GF) mice using
gene expression data and tissue-specific genome-scale metabolic
models (GEMs). We created a generic mouse metabolic reaction
(MMR) GEM, reconstructed 28 tissue-specific GEMs based on
proteomics data, and manually curated GEMs for small intestine,
colon, liver, and adipose tissues. We used these functional
models to determine the global metabolic differences between
CONV-R and GF mice. Based on gene expression data, we found
that the gut microbiota affects the host amino acid (AA)
metabolism, which leads to modifications in glutathione
metabolism. To validate our predictions, we measured the level
of AAs and N-acetylated AAs in the hepatic portal vein of
CONV-R and GF mice. Finally, we simulated the metabolic
differences between the small intestine of the CONV-R and GF
mice accounting for the content of the diet and relative gene
expression differences. Our analyses revealed that the gut
microbiota influences host amino acid and glutathione
metabolism in mice.
This model is hosted on
BioModels Database
and identified by:
MODEL1509220029.
To cite BioModels Database, please use:
BioModels Database:
An enhanced, curated and annotated resource for published
quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.