Assessment of probiotic potential of kimchi-derived lactic acid bacteria with antioxidant and antidiabetic properties.

Kimchi-derived lactic acid bacteria (LAB) have gained increasing attention as functional microorganisms with potential roles in metabolic health. This study aimed to screen and characterize LAB isolated from kimchi for probiotic potential, with a focus on their antioxidant and antidiabetic activities. Three LAB strains with promising functional properties were tentatively identified by partial 16S rRNA gene sequencing as Levilactobacillus brevis KB042-STR, Leuconostoc lactis KH007-STR and Weissella cibaria KH017-STR. Lb. brevis KB042-STR exhibited the strongest antidiabetic activity, with α-glucosidase and α-amylase inhibition of approximately 72% and 64%, respectively (p ≤ 0.05). This strain also demonstrated antioxidant activity, as indicated by high total phenolic content (4.20 ± 0.01 mg GAE/g), strong 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacities. Both Lb. brevis KB042-STR and W. cibaria KH017-STR tolerated simulated gastric conditions (pH 2.0; survival > 50%), while all LAB strains maintained high viability in the presence of bile salts (0.6%), with viable populations remaining above 9 log CFU/mL. In addition, the isolates exhibited high cell surface hydrophobicity and auto-aggregation ability. Notably, Lb. brevis KB042-STR showed significantly greater co-aggregation with pathogens and the strongest adhesion to Caco-2 cells (p ≤ 0.05). All strains were non-haemolytic and susceptible to commonly used antibiotics. These findings expand current knowledge of kimchi-associated LAB and highlight Lb. brevis KB042-STR as a promising multifunctional probiotic candidate, supporting its potential application in functional food or nutraceutical development.