Probiotic and postbiotic interference exhibit anti-adhesion effects against clinical methicillin-resistant Staphylococcus aureus (MRSA) and impede MRSA-induced intestinal epithelial hyper-permeability in HT-29 cell line.

This study investigates the dynamics of MRSA de-colonization on HT-29 cell line using effective strategies like probiotics and postbiotics. Exploring novel alternatives to combat infections caused by antibiotic-resistant pathogens is an urgent need. Harnessing the antagonistic properties of live probiotics and their heat-killed preparations (postbiotics) to curb the growth of AMR pathogens represents a promising and essential area of contemporary research. This study was designed to evaluate the anti-adhesion properties of indigenous probiotics (Limosilactobacillus fermentum Lf1 and Lactiplantibacillus plantarum A5), as well as standard reference strains (Lacticaseibacillus rhamnosus GG and Lactobacillus acidophilus NCFM), and their heat-killed postbiotic preparations against clinical MRSA isolates (MRSA12/206 and 5/255) on the HT-29 cell line. ATR-FTIR-based functional group characterization of the postbiotic preparations revealed the heat-induced alterations in cell surface molecules and architecture. Both probiotic and postbiotic preparations were non-cytotoxic to HT-29 cells. The probiotic intervention, via protective, competitive, and displacement modes, significantly (p < 0.05) reduced the adhesion of MRSA isolates to HT-29 cells, with the protective and competitive modes showing greater efficacy. In contrast, heat-killed probiotics demonstrated notable anti-MRSA adhesion effects across all three modes (protective, competitive, and displacement). In comparison, heat-killed cells exhibited a superior anti-adhesion capability compared to live cells, likely due to the enhanced accessibility of microbe-associated molecular patterns and adhesion sites following heat treatment. Furthermore, co-treatment of MRSA with probiotic strains substantially (p < 0.05) reduced FITC-dextran transflux across the HT-29 cell monolayer. In conclusion, this study highlights the superior anti-adhesion efficacy of heat-killed postbiotics over live probiotic cells against MRSA isolates. It underscores the further need for pre-clinical and in-vivo investigations to validate the anti-MRSA colonization and gut barrier prophylactic or therapeutic potential of the investigated probiotics and postbiotics. Thus, the present study documents and supports the alternative to antibiotics potential of probiotics and postbiotics.