Lactobacillus delbrueckii subsp. lactis CKDB001 Attenuates Hepatic Steatosis and Metabolic Dysfunction in High-Fat Diet–Induced Obese Mice

Metabolic dysfunction associated with obesity frequently coincides with hepatic lipid accumulation; however, effective preventive strategies are scarce. This study evaluated the dose-dependent effects of Lactobacillus delbrueckii subsp. lactis CKDB001 in mice with high-fat diet (HFD)–induced obesity. Male C57BL/6J mice were assigned to a normal diet, HFD, or HFD with CKDB001 at one of three different doses (LL1, 5.0 × 10 8 ; LL2, 1.0 × 10 9 ; LL3, 5.0 × 10 9 CFU/day). Following 4 weeks of HFD feeding, CKDB001 was administered daily for 8 weeks while maintaining the HFD. Among the doses, LL2 demonstrated the most consistent outcomes, including reductions in body weight gain and liver and adipose tissue weights, without affecting food or energy intake. LL2 also decreased serum total cholesterol, alanine aminotransferase levels, hepatic cholesterol content, and histological scores for steatosis, fibrosis, and nonalcoholic fatty liver disease. Although changes in hepatic triglyceride and lipid metabolism-related gene expression were minimal, LL2 and LL3 enhanced colonic Zo-1 and occludin mRNA expression compared to the HFD group, suggesting a potential gut-associated transcriptional response to CKDB001 supplementation.