Highly Adhesive Lactiplantibacillus plantarum ZJ316: Structural Insights of Lipoteichoic Acid and Its Anti-Inflammatory Properties

Lactic acid bacteria are widely recognized for their probiotic properties, and their adhesion to the gastrointestinal tract is a prerequisite for their probiotic functions. This investigation aimed to screen a highly adherent Lactiplantibacillus plantarum (L. plantarum) strain and explore the impact of its surface lipoteichoic acid (LTA) on strain adhesion to intestinal epithelial cells and the immunomodulatory activity. Results demonstrated that L. plantarum ZJ316 exhibited remarkable surface properties and superior adhesion to enterocytes, and the fluorescent labeling revealed that L. plantarum ZJ316 predominantly adhered to the cecum in mice. After comparing four typical separation techniques, the most effective approaches for isolating L. plantarum ZJ316 LTA involved n-butanol extraction combined with ultrahigh pressure cell disruption. Additionally, the structure of purified LTA was characterized by multispectrometric analysis and confirmed as a typical type-I LTA. Furthermore, LTA from L. plantarum ZJ316 dose dependently impacted the adhesion to Caco-2 intestinal epithelial cells, as well as suppressed the expression of inflammatory factors in the LPS-induced RAW264.7 macrophage. Our findings validated that LTA derived from the highly adherent L. plantarum ZJ316 was one of the key adhesion factors and deserved further consideration as an important postbiotic for regulating various immunomodulatory actions.