Lacticaseibacillus rhamnosus WH.FH-19: Probiotic Traits, Fermentation Performance, and Potential for Functional...

Lacticaseibacillus rhamnosus WH.FH-19 exhibits robust probiotic and technological traits for fermented dairy applications. L. rhamnosus WH.FH-19 shows superior functional potential compared to the benchmark strain Lacticaseibacillus rhamnosus GG. Kinetic studies confirm L. rhamnosus WH.FH-19's vigorous growth and rapid acidification kinetics in bovine milk. In vitro characterization reveals enhanced probiotic properties, including significantly greater epithelial adhesion, tolerance to gastrointestinal stresses, cholesterol assimilation capacity, and antioxidant activity. Comprehensive safety assessment demonstrated the absence of hemolysis, sensitivity to clinically relevant antibiotics, and negligible tyramine production. Optimal synergistic fermentation with L. bulgaricus CICC 6047 and S. thermophilus CICC 6038 was achieved using a defined inoculum ratio. Under these conditions, L. rhamnosus WH.FH-19 specifically potentiated the activity of the S. thermophilus strain, accelerating fermentation kinetics without subsequent post-acidification while improving product sensory attributes. These findings establish L. rhamnosus WH.FH-19 as a safe, functionally robust probiotic with significant technological benefit for commercial fermented dairy production.