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Guiberson, E.

Publications and source records attributed to Guiberson, E..

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Fermentation-Derived Metabolites Shape Host Biology to Attenuate Severity of Inflammatory and Metabolic Disease

Fermented foods are among the few dietary interventions shown to increase gut microbiome diversity and reduce systemic inflammation in healthy adults, yet the underlying mechanisms remain poorly defined. Metabolites produced during food fermentation, termed fermentation-derived metabolites (FDMs), represent a largely uncharacterized pool of bioactive compounds that may directly mediate the physiological effects of fermented food consumption. Here, we characterize the metabolite landscape of ten vegetable-based fermented foods using metabolomics, identifying conserved enrichment of aromatic and branched-chain amino acid derivatives across diverse substrates. Using sauerkraut as a chemically representative model system, we show that metabolite extracts from wild green sauerkraut (wGS-FDMs) remodel intestinal and systemic immune populations and shift gut microbiome composition in healthy mice. wGS-FDMs suppressed NF-{kappa}B activation and pro-inflammatory cytokine secretion in vitro and decreased colitis severity in vivo. In a chronic high-fat diet model, wGS-FDMs attenuated weight gain and improved glucose and insulin tolerance, consistent with stimulation of GLP-1 secretion in vitro. Collectively, these findings establish FDMs as biologically potent dietary components capable of simultaneously modulating immune, microbial, and metabolic homeostasis across multiple physiological systems, positioning metabolites from fermented foods as an important and underappreciated class of dietary effectors in the context of chronic disease.

microbiology↗

The Gut Microbiome and Butyrate Differentiate Clostridioides difficile Colonization and Infection in Children

Background and AimsSymptomatic Clostridioides difficile infection (CDI) can cause significant morbidity and mortality. Conversely, patients can be colonized with toxigenic C. difficile in the absence of symptoms, termed asymptomatic colonization. We previously demonstrated that the presence and function of C. difficile toxins do not differentiate between asymptomatic colonization and CDI in children, suggesting the influence of other factors. This study aimed to interrogate the intestinal microbiome and butyrate in stool samples from children with CDI and asymptomatic colonization. MethodsDesign: Case-control study Setting: Tertiary care childrens hospital Participants and measures: Asymptomatic children had stool tested for C. difficile by nucleic-acid amplification-based testing (NAAT) and were considered colonized if positive (N=50). Residual stool was also obtained from symptomatic children who tested positive for C. difficile by NAAT (N=55). The microbiome was assessed via 16S rRNA sequencing and butyrate via liquid chromatography-mass spectrometry. ResultsCompared to clinical co-variates and comorbidities, C. difficile symptom status (i.e., asymptomatic colonization versus symptomatic CDI) demonstrated the strongest differential abundance association on gut microbes. Symptomatic CDI was associated with increased abundance of Escherichia/Shigella (Benjamini-Hochberg adjusted q=3.94x10-5), Haemophilus (q=0.022), and Gemella (q=0.085), and depleted abundance of gut commensals such as Faecalibacterium (q=0.041), Blautia (q=0.041), and Bifidobacterium (q=0.063). We also observed depletion in the abundance of microbial butyrate producers and fecal butyrate in participants with symptomatic CDI versus asymptomatic colonization. ConclusionThe gut microbiota and butyrate differ between participants with asymptomatic C. difficile colonization and symptomatic CDI, suggesting their potential role in symptom development.

microbiology↗

A mutant fitness compendium in Bifidobacteria reveals molecular determinants of colonization and host-microbe interactions

Bifidobacteria commonly represent a dominant constituent of human gut microbiomes during infancy, influencing nutrition, immune development, and resistance to infection. Despite interest as a probiotic therapy, predicting the nutritional requirements and health-promoting effects of Bifidobacteria is challenging due to major knowledge gaps. To overcome these deficiencies, we used large-scale genetics to create a compendium of mutant fitness in Bifidobacterium breve (Bb). We generated a high density, randomly barcoded transposon insertion pool in Bb, and used this pool to determine Bb fitness requirements during colonization of germ-free mice and chickens with multiple diets and in response to hundreds of in vitro perturbations. To enable mechanistic investigation, we constructed an ordered collection of insertion strains covering 1462 genes. We leveraged these tools to improve models of metabolic pathways, reveal unexpected host- and diet-specific requirements for colonization, and connect the production of immunomodulatory molecules to growth benefits. These resources will greatly reduce the barrier to future investigations of this important beneficial microbe.

microbiology↗

Spatially-targeted proteomics of the host-pathogen interface during staphylococcal abscess formation

Staphylococcus aureus is a common cause of invasive and life-threatening infections that are often multi-drug resistant. To develop novel treatment approaches, a detailed understanding of the complex host-pathogen interactions during infection is essential. This is particularly true for the molecular processes that govern the formation of tissue abscesses, as these heterogeneous structures are important contributors to staphylococcal pathogenicity. To fully characterize the developmental process leading to mature abscesses, temporal and spatial analytical approaches are required. Spatially targeted proteomic technologies, such as micro liquid extraction surface analysis, offer insight into complex biological systems including detection of bacterial proteins, and their abundance in the host environment. By analyzing the proteomic constituents of different abscess regions across the course of infection, we defined the immune response and bacterial contribution to abscess development through spatial and temporal proteomic assessment. The information gathered was mapped to biochemical pathways to characterize the metabolic processes and immune strategies employed by the host. These data provide insights into the physiological state of bacteria within abscesses and elucidate pathogenic processes at the host-pathogen interface.

microbiology↗