Project description:Lactobacillus salivarius is a member of the indigenous microbiota of the human gastrointestinal tract (GIT). Tolerance to bile stress is crucial for intestinal lactobacilli to survive in the GIT and to exert their beneficial actions. In this work, the Next-Generation Sequencing platform Illumina HiSeq 2000 was used to investigate the global response to bile in L. salivarius Ren, a potential probiotic strain isolated from a healthy centenarian. In the presence of 0.75 g liter-1 oxgall, the transcription of nearly 200 genes was detected to be associated with bile stress, including genes involved in carbohydrate and amino acid metabolism, cell envelope and fatty acid biogenesis, transcription and translation. This study improves our understanding on bile stress response in L. salivarius Ren.
2019-12-18 | GSE68033 | GEO
Project description:Genomic DNAs of Lactobacillus salivarius (Ligilactobacillus salivarius)
Project description:We used Affymetrix microarrays to investigate gene expression changes in somatic cells from breast-milk extracted from women suffering from mastitis and taking a daily dose of three capsules with ~50 mg of a freeze-dried probiotic (~109 CFU of L. salivarius PS2 strain) for 21 days. Healthy women were subjected to the same treatment for comparison.
Project description:Lactobacillus salivarius, found in the intestinal microbiota of humans and animals, is studied as an example of sub-dominant intestinal commensals that may impart benefits upon their host. Strains typically harbor at least one megaplasmid which encodes functions contributing to contingency metabolism and environmental adaptation. RNA-seq transcriptomic analysis of L. salivarius strain UCC118 identified the presence of a novel long and unusually abundant non-coding RNA (lancRNA) encoded by the megaplasmid and which represented more than 75% of total RNA-seq reads after depletion of ribosomal RNA species. The expression level of this 550 nt lancRNA in L. salivarius UCC118 exceeded that of the 16S rRNA, it accumulated during growth, was very stable over time, and was also expressed during intestinal transit in a mouse. This lancRNA sequence is specific to the L. salivarius species, however among 45 L. salivarius genomes analyzed, not all (only 34) harbored the sequence for the lancRNA. This lancRNA was produced in 27 tested L. salivarius strains but at strain-specific expression levels. High-level lancRNA expression correlated with high megaplasmid copy number. Transcriptome analysis of a deletion mutant lacking this lancRNA identified altered expression levels of genes in a number of pathways but a definitive function of this new long non-coding RNA was not identified. This lancRNA presents distinctive and unique properties, and suggests potential basic and applied scientific developments of this phenomenon.