Project description:Pancreatic cancer is the 3rd most prevalent cause of cancer related deaths in United states alone, with over 55000 patients being diagnosed in 2019 alone and nearly as many succumbing to it. Late detection, lack of effective therapy and poor understanding of pancreatic cancer systemically contributes to its poor survival statistics. Obesity and high caloric intake linked co-morbidities like type 2 diabetes (T2D) have been attributed as being risk factors for a number of cancers including pancreatic cancer. Studies on gut microbiome has shown that lifestyle factors as well as diet has a huge effect on the microbial flora of the gut. Further, modulation of gut microbiome has been seen to contribute to effects of intensive insulin therapy in mice on high fat diet. In another study, abnormal gut microbiota was reported to contribute to development of diabetes in Db/Db mice. Recent studies indicate that microbiome and microbial dysbiosis plays a role in not only the onset of disease but also in its outcome. In colorectal cancer, Fusobacterium has been reported to promote therapy resistance. Certain intra-tumoral bacteria have also been shown to elicit chemo-resistance by metabolizing anti-cancerous agents. In pancreatic cancer, studies on altered gut microbiome have been relatively recent. Microbial dysbiosis has been observed to be associated with pancreatic tumor progression. Modulation of microbiome has been shown to affect response to anti-PD1 therapy in this disease as well. However, most of the studies in pancreatic cancer and microbiome have remained focused om immune modulation. In the current study, we observed that in a T2D mouse model, the microbiome changed significantly as the hyperglycemia developed in these animals. Our results further showed that, tumors implanted in the T2D mice responded poorly to Gemcitabine/Paclitaxel (Gem/Pac) standard of care compared to those in the control group. A metabolomic reconstruction of the WGS of the gut microbiota further revealed that an enrichment of bacterial population involved in drug metabolism in the T2D group.
Project description:Opioids such as morphine have many beneficial properties as analgesics, however, opioids may induce multiple adverse gastrointestinal symptoms. We have recently demonstrated that morphine treatment results in significant disruption in gut barrier function leading to increased translocation of gut commensal bacteria. However, it is unclear how opioids modulate the gut homeostasis. By using a mouse model of morphine treatment, we studied effects of morphine treatment on gut microbiome. We characterized phylogenetic profiles of gut microbes, and found a significant shift in the gut microbiome and increase of pathogenic bacteria following morphine treatment when compared to placebo. In the present study, wild type mice (C57BL/6J) were implanted with placebo, morphine pellets subcutaneously. Fecal matter were taken for bacterial 16s rDNA sequencing analysis at day 3 post treatment. A scatter plot based on an unweighted UniFrac distance matrics obtained from the sequences at OTU level with 97% similarity showed a distinct clustering of the community composition between the morphine and placebo treated groups. By using the chao1 index to evaluate alpha diversity (that is diversity within a group) and using unweighted UniFrac distance to evaluate beta diversity (that is diversity between groups, comparing microbial community based on compositional structures), we found that morphine treatment results in a significant decrease in alpha diversity and shift in fecal microbiome at day 3 post treatment compared to placebo treatment. Taxonomical analysis showed that morphine treatment results in a significant increase of potential pathogenic bacteria. Our study shed light on effects of morphine on the gut microbiome, and its role in the gut homeostasis.
Project description:The link between the gut microbiota and type 2 diabetes (T2D) warrants further investigation because of known confounding effects from antidiabetic treatment. Here we profiled the gut microbiome in a discovery (n=1011) and validation (n=484) cohort comprising Swedish subjects naive for diabetes treatment and grouped by glycemic status.
Project description:Constant availability of food can contribute to the pathogenesis of metabolic syndrome and type 2 diabetes. Short term intermittent fasting (IF) can reset the central, light-entrained (suprachiastmatic nucleus) clock and also the peripheral, food-entrained (liver) clock to restore metabolic homeostasis in T2D. We asked if long term IF could prevent development of diabetic retinopathy (DR) in a type 2 diabetes model, the db/db mouse. After 7 months, IF corrected diabetes-induced increases in triglycerides, cholesteryl esters and diglycerides. IF protocol in db/db mice also prevented development of DR. In addition, host frequency and time of food intake affected the gut microbiome composition. IF led to decreased levels of Clostridiales and Akkermansia muciniphila in db/db mice and these changes in flora were accompanied by increased gut mucin, goblet cell number and villus length. Increased levels of Firmicutes in db/db mice on IF supported improved bile acid metabolism. To confirm that the restoration of bile acid function could contribute to the beneficial effects induced by IF on DR, the dual FXR/TGR-5 agonist INT-767 was administered to a second diabetes model, DBA2J mice injected with streptozotocin (STZ) and placed on Western diet (WD). In this model, INT-767 prevented development of DR. These findings support the concept that long-term IF mediates multiple beneficial effect by restoring the gut-liver axis homeostasis.
Project description:It is well-established that women are disproportionately affected by Alzheimer’s disease (AD). The mechanisms underlying this sex-specific disparity are not fully understood, but several factors that are often associated-including interactions of sex hormones, genetic factors, and the gut microbiome-likely contribute to the disease's etiology. Here, we have examined the role of sex hormones and the gut microbiome in mediating A amyloidosis and neuroinflammation in APPPS1-21 mice. We report that postnatal gut microbiome perturbation in female APPPS1-21 mice leads to an elevation in levels of circulating estradiol. Early stage ovariectomy (OVX) leads to a reduction of plasma estradiol that is correlated with a significant alteration of gut microbiome composition and reduction in A pathology. On the other hand, supplementation of OVX-treated animals with estradiol restores A burden and influences gut microbiome composition. The reduction of A pathology with OVX is paralleled by diminished levels of plaque-associated MGnD-type microglia while estradiol supplementation of OVX-treated animals leads to a restoration of activated microglia around plaques. In summary, our investigation elucidates the complex interplay between sex-specific hormonal modulations, gut microbiome dynamics, metabolic perturbations, and microglial functionality in the pathogenesis of Alzheimer's disease.
2024-02-08 | GSE245831 | GEO
Project description:Gut Microbiome in Type 1 diabetes
Project description:Aging is associated with declining immunity and inflammation as well as alterations in the gut microbiome with a decrease of beneficial microbes and increase in pathogenic ones. The aim of this study was to investigate aging associated gut microbiome in relation to immunologic and metabolic profile in a non-human primate (NHP) model. 12 old (age>18 years) and 4 young (age 3-6 years) Rhesus macaques were included in this study. Immune cell subsets were characterized in PBMC by flow cytometry and plasma cytokines levels were determined by bead based multiplex cytokine analysis. Stool samples were collected by ileal loop and investigated for microbiome analysis by shotgun metagenomics. Serum, gut microbial lysate and microbe-free fecal extract were subjected to metabolomic analysis by mass-spectrometry. Our results showed that the old animals exhibited higher inflammatory biomarkers in plasma and lower CD4 T cells with altered distribution of naïve and memory T cell maturation subsets. The gut microbiome in old animals had higher abundance of Archaeal and Proteobacterial species and lower Firmicutes than the young. Significant enrichment of metabolites that contribute to inflammatory and cytotoxic pathways was observed in serum and feces of old animals compared to the young. We conclude that aging NHP undergo immunosenescence and age associated alterations in the gut microbiome that has a distinct metabolic profile.
Project description:Opioid analgesics are frequently prescribed in the United States and worldwide. However, serious side effects such as addiction, immunosuppression and gastrointestinal symptoms limit long term use. In the current study using a chronic morphine-murine model a longitudinal approach was undertaken to investigate the role of morphine modulation of gut microbiome as a mechanism contributing to the negative consequences associated with opioids use. The results revealed a significant shift in the gut microbiome and metabolome within 24 hours following morphine treatment when compared to placebo. Morphine induced gut microbial dysbiosis exhibited distinct characteristic signatures profiles including significant increase in communities associated with pathogenic function, decrease in communities associated with stress tolerance. Collectively, these results reveal opioids-induced distinct alteration of gut microbiome, may contribute to opioids-induced pathogenesis. Therapeutics directed at these targets may prolong the efficacy long term opioid use with fewer side effects.
Project description:Background/ Aim: Diabetes has substantive co-occurrence with disorders of gut-brain interactions (DGBIs). The pathophysiological and molecular mechanisms linking diabetes and DGBIs are unclear. miRNAs are key regulators of diabetes and gut dysmotility. We investigated whether impaired gut barrier function regulated by a key miRNA, miR-10b-5p, links diabetes and gut dysmotility. Methods: We created a new mouse line using the Mb3Cas12a/Mb3Cpf1 endonuclease to knock out mir-10b globally. Loss of function studies were conducted to characterize diabetes, gut dysmotility, and gut barrier dysfunction phenotypes in these mice. Gain of function studies were conducted by injecting these mice with a miR-10b-5p mimic. Further, we performed miRNA-sequencing analysis from colonic mucosa from mir-10b KO, WT, and miR-10b-5p mimic injected mice to confirm 1) deficiency of miR-10b-5p in KO mice, and 2) restoration of miR-10b-5p expression after the mimic injection. Results: Congenital loss of mir-10b in mice led to the development of hyperglycemia, gut dysmotility, and gut barrier dysfunction. We found increased gut permeability and reduced expression of the tight junction protein Zonula occludens-1 (ZO-1), in the colon of mir-10b KO mice. We further confirmed that patients with diabetes or IBS-C, a known DGBI that is linked to leaky gut, had significantly reduced miR-10b-5p expression. Injection of a miR-10b-5p mimic in mir-10b KO mice rescued these molecular alterations and phenotypes. Conclusion: Our study uncovered a potential pathophysiologic mechanism of gut barrier dysfunction that links both the diabetes and gut dysmotility phenotypes in mice lacking miR-10b-5p. Treatment with a miR-10b-5p mimic reversed the leaky gut, diabetic, and gut dysmotility phenotypes, highlighting the translational potential of miR-10b-5p mimic.
Project description:Age-dependent changes of the gut-associated microbiome have been linked to increased frailty and systemic inflammation. This study found that age-associated changes of the gut microbiome of BALB/c and C57BL/6 mice could be reverted by co-housing of aged (22 months old) and adult (3 months old) mice for 30-40 days or faecal microbiota transplantation (FMT) from adult into aged mice. This was demonstrated using high-throughput sequencing of the V3-V4 hypervariable region of bacterial 16S rRNA gene isolated from faecal pellets collected from 3-4 months old adult and 22-23 months old aged mice before and after co-housing or FMT.