Project description:The gut microbiome is essential for neurodevelopment via bidirectional gut-brain axis signaling, yet environmental chemicals can potentially disrupt this communication by altering community structure and xenobiotic metabolism. In this study, we investigated whether the fungicide azoxystrobin, a known metabolic disruptor, modulates microbiome composition and function to influence neurobehavior. We integrated a simplified human gut microbiota model (SIHUMIx) with a vertebrate host model (larval zebrafish), to elucidate microbiome-mediated mechanisms of xenobiotic neurotoxicity. SIHUMIx was exposed to azoxystrobin for 7 days at 10% of the acceptable daily intake, followed by recovery. Integrated metaproteomic and metabolomic analyses revealed functional reprogramming of the microbiota, characterized by upregulation of vitamin and cofactor biosynthesis, nutrient acquisition, and detoxification pathways, and decreased carbohydrate fermentation and amino acid turnover, consistent with reduced short-chain fatty acid levels. Microbiome-depleted and SIHUMIx-colonized larvae were exposed to azoxystrobin at 4 days post fertilization and neurobehavioral outcomes were assessed after 24 h using the Visual and Acoustic Motor Response assay. Azoxystrobin exposure disrupted non-associative habituation learning independent of microbiome status but induced dark phase-hyperactivity only in colonized larvae, indicating a microbiome-dependent phenotype. Targeted metabolomics revealed lower serotonin levels in microbiome-depleted larvae relative to colonized controls, and that azoxystrobin exposure reduced serotonin in colonized larvae toward depleted levels. These results suggest that microbiota-dependent serotonergic signaling may modulate host responses to azoxystrobin. This integrated ex vivo-in vivo approach supports the concept that the microbiome is a key determinant of neurotoxic responses and underscores the importance of incorporating microbiome-mediated effects into chemical risk assessment frameworks.
2026-04-27 | PXD070601 | Pride
Project description:Solitary bee larvae modify microbial diversity of pollen provisions in the stem-nesting bee, Osmia cornifrons (Megachilidae)
Project description:Host-microbiome-dietary interactions play crucial roles in regulating human health, yet direct functional assessment of their interplays, cross-regulations and downstream disease impacts remains challenging. We adopted metagenome-informed metaproteomics (MIM), in both mice and humans, to simultaneously explore host, dietary, and species-level microbiome interactions across diverse scenarios, including commensal and pathogen colonization, nutritional modifications, and antibiotic-induced perturbations. Implementation of MIM in murine auto-inflammation and in human IBD characterized a ‘compositional dysbiosis’ and a concomitant, species-specific ‘functional dysbiosis’ driven by suppressed commensal responses to inflammatory host signals. Microbiome transfers unraveled early-onset kinetics of these host-commensal cross-responsive patterns, while predictive analyses identified candidate fecal host-microbiome IBD biomarker protein pairs outperforming S100A8/S100A9 (calprotectin). Importantly, a simultaneous fecal nutrient assessment enabled determination of IBD-related consumption patterns, dietary treatment compliance and small-intestinal digestive aberrations. Collectively, a parallelized dietary-bacterial-host MIM assessment functionally uncovers trans-kingdom interactomes shaping gastrointestinal ecology, while offering personalized diagnostic and therapeutic insights into microbiome-associated disease.
Project description:Host-microbiome-dietary interactions play crucial roles in regulating human health, yet direct functional assessment of their interplays, cross-regulations and downstream disease impacts remains challenging. We adopted metagenome-informed metaproteomics (MIM), in both mice and humans, to simultaneously explore host, dietary, and species-level microbiome interactions across diverse scenarios, including commensal and pathogen colonization, nutritional modifications, and antibiotic-induced perturbations. Implementation of MIM in murine auto-inflammation and in human IBD characterized a ‘compositional dysbiosis’ and a concomitant, species-specific ‘functional dysbiosis’ driven by suppressed commensal responses to inflammatory host signals. Microbiome transfers unraveled early-onset kinetics of these host-commensal cross-responsive patterns, while predictive analyses identified candidate fecal host-microbiome IBD biomarker protein pairs outperforming S100A8/S100A9 (calprotectin). Importantly, a simultaneous fecal nutrient assessment enabled determination of IBD-related consumption patterns, dietary treatment compliance and small-intestinal digestive aberrations. Collectively, a parallelized dietary-bacterial-host MIM assessment functionally uncovers trans-kingdom interactomes shaping gastrointestinal ecology, while offering personalized diagnostic and therapeutic insights into microbiome-associated disease.
Project description:The microbiome is an important immune regulator, but the mechanisms by which commensal microbes shape systemic host defense during bloodstream infection remain poorly defined and commonly used pre-clinical models have practical, ethical and scientific limitations. Here, we establish a gnotobiotic zebrafish larval model to investigate microbiome-dependent protection against systemic blood infection by E. coli bacteria, an important cause of early onset neonatal sepsis and nontuberculous mycobacteria to investigate the contribution of Toll-like receptor 2 (TLR2) in the defense responses. Germ-free (GF) and conventionalized (CONVD) larvae derived from the same clutches were systemically infected with E. coli, revealing that microbiome colonization significantly reduces early mortality. RNA-seq revealed a conserved core immune activation program in both GF and CONVD larvae, but the absence of a microbiome was associated with a broader transcriptional response and stronger repression of metabolic pathways, suggesting that commensal microbes buffer infection-induced metabolic suppression. Extending this framework to nontuberculous mycobacteria, we performed systemic infections with fluorescent Mycobacterium marinum and M. avium in tlr2 wild-type and mutant larvae under GF and CONVD conditions. While survival was largely unchanged, imaging-based quantification demonstrated increased bacterial proliferation in tlr2 mutants and in GF larvae, with microbiome-mediated restriction of bacterial burden evident in wild-type but not tlr2-deficient hosts. Together, these data show that microbiome colonization buffers septic outcomes by reshaping systemic inflammatory and metabolic programs, and identify TLR2 as a key node linking microbial colonization to effective host defense during nontuberculous mycobacterial infection
Project description:We preformed a systems biological assessment of lower respiratory tract host immune responses and microbiome dynamics in COVD-19 patients, using bulk RNA-sequencing, single-cell RNA sequencing, and techniques, and microbiome analysis. Are focus was on differential gene expression in severe COVID-19 patients who developed ventilator associated pneumonia (VAP) during their course versus severe COVID-19 patients who did not develop VAP. We found early impairment in antibacterial immune signaling in patients two or more weeks prior to the development of VAP, compared to COVID-19 patients who did not develop VAP. There was no signficant difference in viral load, but an association of disruption in lung microbiome by alpha and beta diversity metrics was also found.