Multi-dimensional screening identifies Lactiplantibacillus plantarum Hi188 and Lacticaseibacillus paracasei Lc19 as probiotics with enhanced gastrointestinal tolerance, organoid adhesion, and barrier protection

The present study established a multi-dimensional screening and functional evaluation system for candidate probiotic strains, integrating tolerance to simulated gastric and intestinal fluids , bile salt resistance, adhesion to intestinal organoids, and intestinal barrier protective capacity. Sixteen candidate probiotic strains were screened using this framework, and Lactiplantibacillus plantarum Hi188 (Hi188) and Lacticaseibacillus paracasei Lc19 (Lc19) consistently performed at levels comparable to or better than the reference strain across all assessed parameters. Both strains maintained high resistance under simulated gastric fluids, intestinal fluids and 0.3% bile salt stress, comparable to the reference strain Lactobacillus rhamnosus GG (LGG), whereas several other strains showed marked reductions, indicating robust gastrointestinal resilience. L. plantarum Hi188 and L. paracasei Lc19 also exhibited significantly higher adhesion to colon organoids, supported by scanning electron microscopy, indicating strong intestinal adhesive potential. In colon organoid models of epithelial injury induced by TNF-α (60 ng/mL, 12 h), both strains effectively restored the expression of tight junction–related genes ( ZO-1 , MUC-2 , CLDN1 and E-cadherin ), with L. paracasei Lc19 additionally upregulating the protein expression levels of Occludin, ZO-1 and E-cadherin, demonstrating their capacity to maintain or repair epithelial barrier integrity under inflammatory stress. These findings reveal a continuous functional chain from gastrointestinal survival to epithelial adhesion to barrier protection, highlighting L. plantarum Hi188 and L. paracasei Lc19 as promising multifunctional probiotics. This multi-dimensional evaluation provides a robust framework for probiotic selection and supports further investigation in animal models and clinical studies to explore their potential for functional food development and intestinal health interventions.