Project description:A study aiming to determine if mice humanized by different donors have different gut microbiota and colonic gene expression patterns in response to the administration of a commonly prescribed, broad-spectrum antibiotic (co-amoxiclav). Male, germ-free mice were humanized by one of two healthy, unrelated human donors. 56 days later, gut microbiota and colonic transcriptome samples were analyzed at baseline, by 454 pyrosequencing and Agilent microarray, respectively. Antibiotics were then administered for 7 days, following by repeated sampling of both the microbiota and colonic RNA at days 8, 11 and 18. Results of the microbiota analysis revealed marked shifts in the composition of one donor group in response to antibiotics and not the other donor group. Transcriptomics revealed a more conserved response, however the magnitude of the effect was greater in the donor group that had a greater shift in the microbiota.
Project description:The microbiota is known to exert substantial effects on shaping an organism's immune system and immune composition of organs. Here we questioned the effect of the microbiota on the transcriptional signature of mouse liver tissue at baseline and during regeneration.
Project description:Advanced age is associated with chronic low-grade inflammation, which is usually referred to as inflammaging. Elderly are also known to have an altered gut microbiota composition. However, whether inflammaging is a cause or consequence of an altered gut microbiota composition is not clear. In this study gut microbiota from young or old conventional mice was transferred to young germ-free mice. Four weeks after gut microbiota transfer immune cell populations in spleen, Peyer’s patches, and mesenteric lymph nodes from conventionalized germ-free mice were analyzed by flow cytometry. In addition, whole-genome gene expression in the ileum was analyzed by microarray. Gut microbiota composition of donor and recipient mice was analyzed with 16S rDNA sequencing. Here we show by transferring aged microbiota to young germ-free mice that certain bacterial species within the aged microbiota promote inflammaging. This effect was associated with lower levels of Akkermansia and higher levels of TM7 bacteria and Proteobacteria in the aged microbiota after transfer. The aged microbiota promoted inflammation in the small intestine in the germ-free mice and enhanced leakage of inflammatory bacterial components into the circulation was observed. Moreover, the aged microbiota promoted increased T cell activation in the systemic compartment. In conclusion, these data indicate that the gut microbiota from old mice contributes to inflammaging after transfer to young germ-free mice.
Project description:This trial evaluates the effects a moderate-to-vigorous exercise intervention has on the bacterial make-up of the gastrointestinal tract (gut microbiota) in survivors of stage II-III colorectal cancer (CRC). Data shows that the gut microbiota composition and function may be drivers of CRC. High levels of exercise are associated with improved CRC prognosis and survival. While data suggests that exercise has the potential to influence gut microbiota composition and function, it is not known whether these effects contribute to improved CRC prognosis. This clinical trial evaluates the effects an exercise intervention has on gut microbiota and how these effects relate to CRC progression and patient-reported outcomes.
Project description:Insect gut microbiota plays important roles in acquiring nutrition, preventing pathogens infection, immune responses, and communicating with the environment. Gut microbiota can be affected by some external factors such as foods, temperature, and antibiotics. Spodoptera frugiperda (Lepidoptera: Noctuidae) is an important destructive pest of grain crops all over the world. The function of gut microbiota in S. frugiperda remains to be investigated. In this study, we fed the S. frugiperda with the antibiotic mixture (penicillin, gentamicin, rifampicin, and streptomycin) to perturb the gut microbiota, and further examined the effect of dysbiosis in gut microbiota on the gene expression of S. frugiperda by RNA sequencing. We found the composition and diversity of the gut bacterial community were changed in S. frugiperda after antibiotics treatmen, and the expression of genes related to energy and metabolic process were affected after antibiotics exposure in S. frugiperda. Our work will help understand the role of gut microbiota in insects.
Project description:Morphine and its pharmacological derivatives are the most prescribed analgesics for moderate to severe pain management. However, chronic use of morphine reduces pathogen clearance and induces bacterial translocation across the gut barrier. The enteric microbiome has been shown to play a critical role in the preservation of the mucosal barrier function and metabolic homeostasis. Here, we show for the first time, using bacterial 16s rDNA sequencing, that chronic morphine treatment significantly alters the gut microbial composition and induces preferential expansion of the gram-positive pathogenic and reduction of bile-deconjugating bacterial strains. A significant reduction in both primary and secondary bile acid levels was seen in the gut, but not in the liver with morphine treatment. Morphine induced microbial dysbiosis and gut barrier disruption was rescued by transplanting placebo-treated microbiota into morphine-treated animals, indicating that microbiome modulation could be exploited as a therapeutic strategy for patients using morphine for pain management. In this study, we establish a link between the two phenomena, namely gut barrier compromise and dysregulated bile acid metabolism. We show for the first time that morphine fosters significant gut microbial dysbiosis and disrupts cholesterol/bile acid metabolism. Changes in the gut microbial composition is strongly correlated to disruption in host inflammatory homeostasis13,14 and in many diseases (e.g. cancer/HIV infection), persistent inflammation is known to aid and promote the progression of the primary morbidity. We show here that chronic morphine, gut microbial dysbiosis, disruption of cholesterol/bile acid metabolism and gut inflammation; have a linear correlation. This opens up the prospect of devising minimally invasive adjunct treatment strategies involving microbiome and bile acid modulation and thus bringing down morphine-mediated inflammation in the host.
Project description:Accumulating evidence demonstrates that the gut microbiota affects brain function and behavior, including depressive behavior. Antidepressants are the main drugs used for treatment of depression. We hypothesized that antidepressant treatment could modify gut microbiota which can partially mediate their antidepressant effects. Mice were chronically treated with one of five antidepressants (fluoxetine, escitalopram, venlafaxine, duloxetine or desipramine), and gut microbiota was analyzed, using 16s rRNA gene sequencing. After characterization of differences in the microbiota, chosen bacterial species were supplemented to vehicle and antidepressant-treated mice, and depressive-like behavior was assessed to determine bacterial effects. RNA-seq analysis was performed to determine effects of bacterial treatment in the brain. Antidepressants reduced richness and increased beta diversity of gut bacteria, compared to controls. At the genus level, antidepressants reduced abundances of Ruminococcus, Adlercreutzia, and an unclassified Alphaproteobacteria. To examine implications of the dysregulated bacteria, we chose one of antidepressants (duloxetine) and investigated if its antidepressive effects can be attenuated by simultaneous treatment with Ruminococcus flavefaciens or Adlercreutzia equolifaciens. Supplementation with R. flavefaciens diminished duloxetine-induced decrease in depressive-like behavior, while A. equolifaciens had no such effect. R. flavefaciens treatment induced changes in cortical gene expression, up-regulating genes involved in mitochondrial oxidative phosphorylation, while down-regulating genes involved in neuronal plasticity. Our results demonstrate that various types of antidepressants alter gut microbiota composition, and further implicate a role for R. flavefaciens in alleviating depressive-like behavior.