A Biomimetic gut-on-a-chip Integrated with Multi-Omics Reveal the Mechanism of Listeria monocytogenes Infection Microenvironment-Stimulated In Situ Bacteriocin Production by Lactiplantibacillus paraplantarum RX-8.
Abstract
Bacteriocins produced in intestine by lactic acid bacteria (LAB) can suppress pathogens and support homeostasis, offering potential against foodborne bacterial infections. However, complex in vivo intestinal milieu hampers monitoring of bacteriocin production and its regulation during enteric infection. Herein, we developed and first applied a three-dimensional gut-on-a-chip with an intact mucus layer, robust barrier function, and stable immune homeostasis to dynamically examine bacteriocin biosynthesis during infection. Compared with its bacteriocin gene-deletion mutant, L. paraplantarum RX-8 reduced adherent L. monocytogenes by 2.69 lg CFU/mL, preserved mucin and tight-junction integrity, and suppressed pro-inflammatory cytokine release, highlighting the anti-infective role of in situ-produced plantaricin. Although infection modestly reduced L. paraplantarum RX-8 density, it reshaped plnA dynamics, enhanced plnBCD, plaRX, pfs, and luxS transcription, AI-2 activity, and plantaricin RX-8 production 2.25-fold, suggesting coordinated regulation by intraspecies PlnA and interspecies LuxS/AI-2 quorum-sensing (QS) systems. Integrated multi-omics analysis linked this QS-associated phenotype to metabolic, environmental-sensing, and transport reprogramming. Enhanced carbohydrate uptake, pyruvate oxidation, electron transport, and riboflavin metabolism may support ATP generation, redox homeostasis, and stress adaptation. Sulfur-containing amino acid metabolism may shift from de novo synthesis toward the activated methyl cycle and AI-2-associated processes, while altered two-component signaling, ABC transport, and SecYEG/YidC-associated export may enhance signal sensing, nutrient acquisition, and plantaricin biosynthesis and secretion. Finally, infection-responsive sRNA0019 was predicted to target plnA and luxS, suggesting a candidate post-transcriptional regulatory layer for both QS systems. These findings provide multilevel insights into bacteriocin biosynthesis during intestinal infection, supporting the efficient application of bacteriocin-producing LAB.
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