Project description:D-galactose orally intake ameliorate DNCB-induced atopic dermatitis by modulating microbiota composition and quorum sensing. The increased abundance of bacteroidetes and decreased abundance of firmicutes was confirmed. By D-galactose treatment, Bacteroides population was increased and prevotella, ruminococcus was decreased which is related to atopic dermatitis.
Project description:Here we report 16S rRNA data in gut microbiota of autism spectrum disorders compared with healthy volunteers. A total of 1322 operational taxonomic units (OTUs) were identified in the sequence data. The Bacteroidetes and Firmicutes were both dominated phylum in ausitic subjects and healthy controls. Phylum level analysis showed a clear alteration of the bacterial gut community in ASD characterized by a higher Firmicutes (P < 0.05), Proteobacteria (P < 0.001), and Actinobacteria (P < 0.001) than that in healthy controls. However, Bacteroidetes were significantly decreased in ASD patients (P < 0.001).
Project description:In Proteobacteria, the outer membrane protein TamA and the inner membrane-anchored protein TamB form the Translocation and Assembly Module (TAM) complex, which facilitates the transport of autotransporters, virulence factors, and likely lipids across the two membranes. In Bacteroidetes, TamB co-occurs with TamL, a TamA-like lipoprotein with a lipid modification at its N-terminus that likely anchors it to the outer membrane. This structural difference suggests that TamL may have a distinct function compared to the TamA homologue in Proteobacteria. However, the role of TAM in bacterial phyla other than Proteobacteria remains unexplored. Our study aimed to elucidate the functional importance of TamL in Flavobacterium johnsoniae, an environmental Bacteroidetes. Unlike its homologues in Proteobacteria, we found that TamL and TamB are essential in F. johnsoniae. Through genetic, phenotypic, proteomic, and lipidomic analyses, we discovered that TamL depletion severely compromises outer membrane integrity, as evidenced by reduced cell viability, altered cell shape, increased susceptibility to membrane-disrupting agents, and elevated levels of outer membrane lipoproteins. Notably, we did not observe any impact on outer membrane lipid composition. Via pull-down protein assays, we confirmed that TamL interacts with TamB in F. johnsoniae, likely forming the TAM complex. Furthermore, our in silico analysis revealed that the presence of TamL and TamB monocistronic genes is a shared genetic feature among Bacteroidetes members, including the human pathogen Capnocytophaga canimorsus where we confirmed the essentiality of the TamL and TamB homologs. To our knowledge, this study is the first to provide functional insights into a TAM subunit beyond Proteobacteria.
Project description:We sampled global bottom up proteomics data from 48 diverse bacteria and searched for sites of lysine acetylation. Bacteria came from 6 phyla: proteobacteria, cyanobacteria, firmicutes, bacteroidetes, actinobacteria, and fibrobacteres.
Project description:The gut microbiome shapes local and systemic immunity. The liver is presumed to be a protected sterile site. As such, a hepatic microbiome has not been examined. Here, we show that the liver hosts a robust microbiome in mice and humans that is distinct from the gut and is enriched in Proteobacteria. It undergoes dynamic alterations with age and is influenced by the environment and host physiology. Fecal microbial transfer experiments revealed that the liver microbiome is populated from the gut in a highly selective manner. Hepatic immunity is dependent on the microbiome, specifically Bacteroidetes species. Targeting Bacteroidetes with oral antibiotics reduced the hepatic immune cell infiltrate by ~90%, prevented APC maturation, and mitigated adaptive immunity. Mechanistically, presentation of Bacteroidetes-derived glycosphingolipids to NKT cells promotes CCL5 signaling, which drives hepatic leukocyte expansion and maturation. Collectively, we reveal a microbial – glycosphingolipid – NKT – CCL5 axis that underlies hepatic immunity.
Project description:Eutrophication can lead to an uncontrollable increase in algal biomass, which has repercussions for the entire microbial and pelagic community. Studies have shown how nutrient enrichment affects microbial species succession, however details regarding the impact on community functionality are rare. Here, we applied a metaproteomic approach to investigate the functional changes to algal and bacterial communities, over time, in oligotrophic and eutrophic conditions, in freshwater microcosms. Samples were taken early during algal and cyanobacterial dominance and later under bacterial dominance. 1048 proteins, from the two treatments and two timepoints, were identified and quantified by their exponentially modified protein abundance index. In oligotrophic conditions, Bacteroidetes express extracellular hydrolases and Ton-B dependent receptors to degrade and transport high molecular weight compounds captured while attached to the phycosphere. Alpha- and Beta-proteobacteria were found to capture different substrates from algal exudate (carbohydrates and amino acids, respectively) suggesting resource partitioning to avoid direct competition. In eutrophic conditions, environmental adaptation proteins from cyanobacteria suggested better resilience compared to algae in a low carbon nutrient enriched environment. This study provides insight into differences in functional microbial processes between oligo- and eutrophic conditions at different timepoints and highlights how primary producers control bacterial resources in freshwater environments.