Excessive dietary copper is a nutritional toxicant that disrupts homeostasis and provokes liver injury; yet the role of cuproptosis (copper-dependent cell death) is not fully defined. Tamarixetin (TAM), a food-derived flavonoid with copper-chelating and antioxidant capacity, was evaluated as a protective bioactive. We demonstrate that copper overload drives hepatotoxicity predominantly through cuproptosis. TAM lowered labile copper and activated the nuclear receptor NR1I2, thereby upregulating lipoic acid synthase (LIAS) to inhibit cuproptosis and restore tricarboxylic acid cycle function. NR1I2 overexpression phenocopied TAM-mediated protection, confirming the NR1I2–LIAS axis. TAM also reshaped the gut microbiota, enriching Lactobacillus and, via the gut–liver axis, suppressing NF-κB–mediated hepatic inflammation. Overall, these findings reveal a flavonoid–metal interaction-based defense mechanism and support TAM as a functional ingredient or nutraceutical to mitigate high dietary copper exposure.

Sepsis remains a leading cause of mortality worldwide, driven by dysregulated inflammation and organ failure, with limited targeted therapies. Pyroptosis, mediated by gasdermin D (GSDMD), amplifies sepsis pathology through lipid peroxidation-dependent mechanisms, yet direct interventions are scarce. Leveraging the probiotic Escherichia coli Nissle 1917 (EcN) for gut-targeted delivery, we engineered EcN to secrete glutathione peroxidase 4 (GPX4), a pivotal antioxidant enzyme that curbs lipid peroxidation and pyroptosis. In an LPS-induced murine sepsis model, prophylactic oral EcN-GPX4 enhanced survival, mitigated multi-organ damage, and suppressed GSDMD cleavage across tissues. Dual mechanisms included: alleviation of oxidative stress and lipid peroxidation to block pyroptosis; and gut microbiota remodeling, enriching Ligilactobacillus murinus, which correlated with reduced LPS translocation and dampened arachidonic acid–linked pro-inflammatory metabolism. Via the gut–liver axis, EcN-GPX4 further attenuated hepatic TLR4/NF-κB signaling. This probiotic-based enzyme delivery offers a precise, microbiome-modulating strategy to interrupt pyroptotic amplification, with strong translational promise for sepsis management.

Iron is the most abundant trace element in the human body, and both deficiency and overload can adversely impact health. Escherichia coli (E. coli), a widespread foodborne pathogen found in food and animal environments, poses a significant public health risk and is a leading cause of infectious diarrhea. While most E. coli strains exhibit low virulence, those carrying high-pathogenicity islands (HPI) display increased pathogenicity. In this study, we isolated E. coli strains containing HPI and utilized CRISPR-Cas9 technology to delete the ybtA gene, inactivating the HPI and reducing pathogenicity. We further explored the mechanisms by which this pathogen damages human intestinal epithelial cells. Tandem Mass Tag (TMT) proteomics and metabolomics analyses revealed that the PI3K-AKT pathway plays a critical role in E. coli infection, generating inflammatory mediators, primary metabolites of arachidonic acid (ARA), which are linked to the presence of HPI. Additionally, Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analysis showed a significant rise in iron ion levels in the intestines of infected mice. To further investigate this mechanism, we supplemented cultured human intestinal epithelial cells with FeSO4. Subsequent proteomic and metabolomic analyses demonstrated that FeSO4 supplementation further increased the virulence of HPI-rich E. coli, leading to intracellular iron overload. This overload-induced oxidative stress and lipid peroxidation, ultimately causing ferroptosis in the intestinal epithelial cells. Moreover, iron enhanced the NLRP3 pyroptosis pathway induced by E. coli, mainly by promoting the assembly of the NLRP3 inflammasome and the release of GSDMD-N, which facilitated further pyroptosis in the intestinal epithelial cells. In conclusion, our findings show that foodborne E. coli infection induces intestinal iron overload, which, with the aid of iron, enhances the pathogen's virulence, leading to ferroptosis and pyroptosis in intestinal epithelial cells. This process triggers an inflammatory cytokine storm, resulting in significant intestinal damage.