Project description:Secreted phospholipase A2-IIA (sPLA2-IIA) hydrolyzes phospholipids to liberate lysophospholipids and fatty acids. Given its poor activity toward eukaryotic cell membranes, its role in the generation of proinflammatory lipid mediators is unclear. Conversely, sPLA2-IIA efficiently hydrolyzes bacterial membranes. Here, we show that sPLA2-IIA impacts on the immune system by acting on the intestinal microbial flora. Using mice overexpressing transgene-driven human sPLA2-IIA, we found that the intestinal microbiota was critical for both induction of an immune phenotype and promotion of inflammatory arthritis. The expression of sPLA2-IIA led to alterations of the intestinal microbiota composition, but housing in a more stringent pathogen-free facility revealed that its expression could affect the immune system in the absence of changes to the composition of this flora. In contrast, untargeted lipidomic analysis focusing on bacteria-derived lipid mediators revealed that sPLA2-IIA could profoundly alter the fecal lipidome. The data suggest that a singular protein, sPLA2-IIA, produces systemic effects on the immune system through its activity on the microbiota and its lipidome.
Project description:Folic acid deficiency is common worldwide and is linked to intestinal flora imbalance. The intestinal microbial utilization of folic acid based on model animals faces the challenges of repeatability and individual variability. In this study, we built an in vitro fecal slurry culture model deficient in folic acid. We examined the effects of supplementation with different forms of folic acid (5-methyltetrahydrofolate and non-reduced folic acid) on the modulation of intestinal flora. 16S rDNA gene sequencing showed alpha diversity increased after folic acid supplementation compared to fermentation samples with folic acid deficiency. In the non-reduced folic acid (FA) group, the relative abundance of the Firmicutes phylum dropped to 56.7%, whereas in the 5-methyltetrahydrofolate (MTHF) supplementation group, it grew to 64.9%. Lactobacillus genera became more prevalent, reaching 22.8% and 30.8%, respectively. Additionally, Bifidobacterium and Pedioccus, two common probiotic bacteria, were in higher abundance. Short-chain fatty acids (SCFAs) analysis showed that supplementation with folic acid (non-reduced folic acid, 5-methyltetrahydrofolate) decreased acetic acid and increased the fermentation yield of isobutyric acid. The in vitro fecal slurry culture model developed in this study can be utilized as a human folic acid deficiency model for studying intestinal microbiota and demonstrated that both 5-methyltetrahydrofolate and non-reduced folic acid have effects on the regulation of intestinal microecology.
Project description:Morphine causes microbial dysbiosis. In this study we focused on restoration of native microbiota in morphine treated mice and looked at the extent of restoration and immunological consequences of this restoration. Fecal transplant has been successfully used clinically, especially for treating C. difficile infection2528. With our expanding knowledge of the central role of microbiome in maintenance of host immune homeostasis17, fecal transplant is gaining importance as a therapy for indications resulting from microbial dysbiosis. There is a major difference between fecal transplant being used for the treatment of C. difficile infection and the conditions described in our studies. The former strategy is based on the argument that microbial dysbiosis caused by disproportionate overgrowth of a pathobiont can be out-competed by re-introducing the missing flora by way of a normal microbiome transplant. This strategy is independent of host factors and systemic effects on the microbial composition. Here, we show that microbial dysbiosis caused due to morphine can be reversed by transplantation of microbiota from the placebo-treated animals.
Project description:We aimed to investigate the microbial community composition in patients with intracerebral hemorrhage (ICH) and its effect on prognosis. The relationship between changes in bacterial flora and the prognosis of spontaneous cerebral hemorrhage was studied in two cohort studies. Fecal samples from healthy volunteers and patients with intracerebral hemorrhage were subjected to 16S rRNA sequencing at three time points: T1 (within 24 hours of admission), T2 (3 days post-surgery), and T3 (7 days post-surgery) using Illumina high-throughput sequencing technology.
Project description:Starting from the evidences of gut microbiota role in tumor development, progression and response to therapy, this project was aimed at evaluating the effect of antibiotic treatment on intestine. The intestinal flora of FVB mice was altered by the oral administration of vancomicyn, mice were then injected with MI6 cells, a singeneic tumor cells line established from spontanueous mammary tumor developped in transgenic d16HER2-transgenic mice [Castagnoli L, 2014]. To analyze the impact of vancomycin on intestinal mucosa, a gene expression profile was performed on colon and ileum samples.
Project description:Habitual exercise modulates the composition of the intestinal microbiota. We examined whether transplanting fecal microbiota from trained mice improved skeletal muscle metabolism in high-fat diet-fed mice. The recipient mice that received fecal samples from trained donor mice for 1 week showed elevated levels of metabolic signalings in skeletal muscle. Glucose tolerance was improved by fecal microbiota transplantation after 8 weeks of HFD administration. Intestinal microbiota may mediate exercise-induced metabolic improvement in mice. We performed a microarray analysis to compare the metabolic gene expression profiles in the skeletal muscle from each mouse.
Project description:To explore the regulatory mechanism of intestinal flora in Citrobacter rodentium -induced intestinal infection by transcriptome analysis at miRNA molecular level.