Fig. 4.

Telomere length as measured by quantitative polymerase-chain reaction using genomic DNA. 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. *P<0.05.