<em>Lactiplantibacillus plantarum</em> lipoteichoic acid as a key surface molecule in immune enhancement and pathogen defense

Lipoteichoic acid (LTA), a bacterial cell surface macromolecule, plays a key role in probiotic–host interactions by engaging host pattern recognition receptors in the gastrointestinal mucosa. This study investigates the potential of <em>Lactiplantibacillus plantarum</em> LTA in combating intestinal pathogens and supporting gut health. We demonstrate that <em>L. plantarum</em> LTA, acting as a biosurfactant, significantly inhibits biofilm formation by various intestinal pathogens, including <em>Escherichia coli</em>, <em>Salmonella typhimurium</em>, <em>Staphylococcus aureus</em>, and<em> Listeria monocytogenes</em>. This is achieved by disrupting biofilm structures, reducing extracellular polymer secretion, and downregulating biofilm-related gene expression. Additionally, LTA effectively prevents pathogen adhesion to Caco-2 cells and reduces <em>Escherichia coli</em>-induced apoptosis. LTA also modulates macrophage inflammation by regulating cytokine secretion and decreasing NO and ROS production through the TLR4-MAPK-NF-κB signaling pathway. These findings provide valuable insights into the mechanisms by which <em>L. plantarum</em> LTA supports gut health and highlight its potential applications in preventing intestinal pathogen colonization and enhancing immune modulation.