Yogurt application and postbiotic effects on mouse intestinal cells of Lacticaseibacillus paracasei HKWS110 isolated from Prunus yedoensis.

Lacticaseibacillus paracasei is a lactic acid bacterium with potential health-promoting properties. However, its probiotic and postbiotic effects have not been fully characterized when isolated from plant sources such as Prunus yedoensis. In this study, we evaluated the fermentation performance, antioxidant activity, and biological effects of L. paracasei isolated from P. yedoensis, with a particular focus on its impact on yogurt quality and intestinal epithelial cell health. Fermentation characteristics were assessed by monitoring pH, titratable acidity, viable cell counts, viscosity, and antioxidant activity in yogurt fermented with L. paracasei, both alone and in combination with a commercial starter culture (YC-380). The biological effects of its cell-free supernatant on mouse small intestinal cells were evaluated using western blotting, ELISA, immunofluorescence, and zymography. L. paracasei reached a viable cell count of 9.74 log CFU/mL after 60 h, showing slower initial growth compared to Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus. Co-fermentation with YC-380 enhanced lactic acid production and overall fermentation efficiency. Yogurt fermented with L. paracasei exhibited the highest antioxidant activity, along with improved viscosity and storage stability. The cell-free supernatant of L. paracasei increased cell viability, proliferation, and metabolic activity at 10 µg/mL, whereas higher concentrations (30 µg/mL) activated IGF/mTOR signaling and induced apoptosis via Caspase-3. Extracellular matrix remodeling markers, such as MMP-2 and MMP-9, were also modulated in a concentration-dependent manner. Overall, L. paracasei isolated from P. yedoensis exhibits strong probiotic and postbiotic potential. Its incorporation into yogurt fermentation enhances product quality and exerts beneficial effects on intestinal epithelial cells, supporting its potential as a functional ingredient in dairy and gut health–focused applications.