Fig. 5.

Fold-change of gene expression levels for molecular markers involved in (A) apoptosis as determined using the FAS gene, (B) senescence as determined using the cyclin D1 gene, and oxidative stress using (C) the glutathione peroxidase (GPX) gene and (D) superoxide dismutase (SOD) gene following 12 weeks of treatment. Treatment groups include: Young, naïve rats receiving 0.9% saline via subcutaneous injection daily; Old, rats receiving 600 mg/kg D-galactose via subcutaneous injection to induce aging; Old+4189, aged rats treated with Limosilactobacillus fermentum USM 4189 (1×10¹⁰ CFU/d) via oral administration; Old+metformin, aged rats treated with metformin (300 mg/kg/d) via oral administration. The results are expressed as the mean±SE; n=6. Statistical analysis was conducted using an independent t-test.