Project description:Background: Probiotic-like bacteria treatment has been described to be associated with gut microbiota modifications. Goal: To decipher if the effects of the tested probiotic-like bacteria are due to the bacteria itself or due to the effects of the bacteria on the gut microbiota. Methodology: In this study, gut microbiota has been analyzed from feces samples of subjects with metabolic syndrome and treated with one of the 2 tested probiotic-like bacteria or with the placebo during 3months.
Project description:Escherichia coli Nissle 1917 (EcN) is a probiotic used for treatment of intestinal disorders. EcN improves gastrointestinal homeostasis and microbiota balance; however little is known about how this probiotic delivers effector molecules to the host. Outer membrane vesicles (OMVs) are constitutively produced by gram-negative bacteria and have a relevant role in bacteria-host interactions. Here we performed proteomic analysis of EcN OMVs. Using 1D SDSD-PAGE and highly sensitive LC-MS/MS analysis we identified 192 EcN vesicular proteins with high confidence in three independent experiments. Of these proteins, 18 were encoded by strain-linked genes and 57 were common to pathogen-derived OMVs. These proteins may contribute to the ability of this probiotic to colonize the human gut as they fulfil functions related to adhesion to host tissues, immune modulation or bacterial survival in host niches. This study describes the first global OMV proteome of a probiotic strain and provides evidence that probiotic-derived OMVs contain proteins that can target these vesicles to the host and mediate their beneficial effects on intestinal function.
Project description:<p>A mechanistic understanding of the health benefits conferred by consumption of probiotic bacteria has been limited by our knowledge of the resident gut microbiota and its interaction with the host. We used fecal samples from a study of twelve healthy individuals aged 65-80 to characterize the structure and functional dynamics of the gut microbiota associated with consumption of the single-organism probiotic, Lactobacillus rhamnosus GG ATCC 53103 (LGG). Samples were collected prior to probiotic consumption (day 0), on day 28 immediately after consuming 10^10 CFU of LGG twice daily for 28 days and day 56, one month after stopping LGG consumption. Our integrative approach incorporated bacterial 16S rRNA gene sequencing, whole-community expression profiling using RNA-seq, and metagenomic sequencing. We highlight the value of combinatorial 'omics methods and concomitant high-resolution informatics to probe the role that probiotics may play on the structure and function of the resident microbiota.</p>
Project description:The rate of probiotic usage by pregnant women in the US and Canada ranges from 1.3 to 3.6 %. Probiotic supplements are available without a prescription and have gained currency in treating a variety of ailment ranging from reducing risk of constipation, diarrhea, other gastrointestinal conditions, eczema, pre-term birth, and prevent adverse pregnancy outcomes, including gestational diabetes mellitus (GDM) and depression/anxiety. Three possible mechanisms by which maternal probiotic supplementation might influence the placenta are through 1) directly impacting possible bacteria residing in the placenta (placenta microbiome), 2) altering bacterial metabolites produced by gut microbiota within the mother that induce placental changes, and 3) maternal probiotics might affect the composition of the bacteria within the maternal gut that affects her immune cells and their responses to the heterologous placenta. For the second potential mechanism, bacterial metabolites that might influence placenta include short chain fatty acids (SCFAs), polyamines (PAs), and Vitamins B9 (Folic Acid) and 12 (Cobalamin), among others. This project aims to determine the effects maternal probiotic supplementation in mice might have on the fetal placenta. With the number of women taking over probiotic supplements increasing, further research is needed to determine how these bioactive agents may affect the placenta and health of the offspring.
Project description:Bacteria that colonize the human gut must withstand a variety of stressors, including detergent-like compounds known as bile acids. Here, we investigated how bile acids found in the human cecum and colon impact the behavior of the probiotic strain Escherichia coli Nissle 1917 (EcN). We found that lithocholic acid (LCA), which is a microbiota-derived secondary bile acid, promotes the formation of a distinctive surface-coating biofilm by EcN, including on an organoid-derived model of the human colonic epithelium. Mechanistic investigations, including RNA-sequencing, revealed that LCA upregulates the production of several components of flagella, which are essential for LCA-induced biofilm formation and form part of the biofilm extracellular matrix.
Project description:Modulation of gut microbiota through probiotic supplementation is an interesting strategy to prevent obesity We use microarrays to study the global genome expression of C. elegans fed with the probiotic strain Bifidobacterium animalis sbsp. lactis CECT 8145