Lactobacillus gasseri LG 2361 from infant feces synergizes with Lactobacillus acidophilus ATCC 43121 to lower lipids in high-fat fed mice

Hyperlipidemia impose a substantial burden on human health. Recent studies have demonstrated that probiotics can regulate lipid metabolism by modulating gut microbiota composition or producing bioactive metabolites, with human-derived strains potentially exhibiting superior host colonization capacity. This study isolated Lactobacillus gasseri LG 2361 from 84 healthy infant fecal samples. Safety assessments confirmed non-hemolytic activity, antibiotic susceptibility (except natural resistance), and gastrointestinal adaption (81 % survival at pH 3.0; 60 % survival at 0.1 % bile). The strain demonstrated lipid-lowering capacity in vitro , degrading 43.0 % cholesterol and 34.6 % triglycerides. In high-fat diet mice, LG 2361 reduced hepatic lipid accumulation (11.6 % total cholesterol, p < 0.05), attenuated abdominal adiposity (32.9 % subcutaneous fat reduction, p < 0.01), and may enhance antioxidant status (22.5 % glutathione peroxidase increase, p < 0.01). Synergy with L . acidophilus ATCC 43121 amplified efficacy, achieving 61.6 % abdominal fat reduction (p < 0.01) while suppressing TNF-α (0.46-fold) and IL-1β (0.29-fold, p < 0.001). Mechanistically, LG 2361 downregulated PPARγ (0.59-fold, p < 0.01) and modulated FAT/CD36 pathways, indicating dual regulation of lipogenesis and lipid transport. These findings suggest that LG 2361 may be a probiotic candidate for hyperlipidemia management.