Comparative Effects of Lactose-Free and Regular Kefir on Lifespan of Drosophila Melanogaster

This study investigated the effects of lactose-free and regular kefir on Drosophila melanogaster lifespan, by applying four doses (5%, 10%, 15%, 20%) to assess their impact on aging through mathematical modeling. We hypothesized that kefir's probiotic content could extend lifespan through its bioactive compounds, with the observed differences potentially attributable to lactose content and dosage. Wild-type flies were divided into groups: a control group fed with a standard diet (SDB), and groups fed regular or lactose-free kefir at varying concentrations. Each group comprised 100 male and 100 female flies, with three replicates, maintained at 25°C and 60% humidity. Daily survival data were collected and analyzed using the Gompertz model to evaluate lifespan and aging rates. Results showed that regular 15% kefir increased average lifespan from 61.2 to 68.2 days for females, and 63.5 to 70.0 days for males, while lactose-free kefir at the same dose extended it to 72.4 and 73.9 days, respectively. Aging rates decreased most significantly at 15% lactose-free kefir, indicating slower aging. However, at 20%, lifespan gains diminished, indicating a complex dose-response relationship that warrants further investigation. These findings suggest kefir's anti-aging potential, with lactose-free kefir showing greater efficacy (18.3% increase in females and 16.4% increase in males), and highlight the importance of dose optimization in aging research.