Efficacy of Lactococcus lactis WiKim0124 in Fat-, Sucrose-, and Fat/Sucrose-Induced Obesity Models

Lactococcus lactis WiKim0124 (WiKim0124), a probiotic strain isolated from kimchi, has previously shown anti-obesity effects in high-fat diet (HFD) models. This study investigated whether WiKim0124 and its formulated version, SW01, exert consistent anti-obesity efficacy across distinct diet-induced obesity models through modulation of host lipid metabolism and gut microbial function. In 3T3-L1 adipocytes and FFA-treated HepG2 cells, both treatments inhibited lipid accumulation and modulated lipid metabolism–related markers, indicating enhanced fatty acid oxidation and reduced lipogenesis. In C57BL/6 J mice fed HFD, high-sucrose (HSuc), or HFD + HSuc diets, daily oral administration of WiKim0124 or SW01 significantly reduced body weight gain, adipose tissue mass, and hepatic lipid accumulation. WiKim0124 and SW01 significantly enhanced fatty acid oxidation pathways, as evidenced by increased expression of the markers PPARα, CPT-1α, and UCP2. Gut microbiota analysis showed increased Bacteroidetes and enrichment of Akkermansia muciniphila in treated groups. Shotgun metagenomic functional profiling revealed enhanced short-chain fatty acid–related pathways and enzymes, with distinct patterns depending on treatment and dietary stressors. Microbial functional responses were most pronounced in the HFD + HSuc model, supporting a diet-dependent mode of probiotic action. Together, these findings demonstrate consistent anti-obesity efficacy of WiKim0124 and support the translational potential of its formulated application through integrated modulation of host metabolism and gut microbial function.