Microbiota-Dependent Longevity Effects of Aronia Berry (Aronia melanocarpa) in Drosophila melanogaster

Aronia berry (Aronia melanocarpa) is rich in polyphenolic compounds with reported antioxidant and prebiotic activities, including potential life-extending effects. Although previous studies have highlighted its impact on the gut microbiota, the extent to which commensal microbes contribute to its longevity effects remains poorly understood. Here, we aimed to determine whether the lifespan- and health-promoting effects of Aronia berry are mediated by commensal microbes and to elucidate the underlying mechanisms. To address this, we investigated the effects of Aronia berry supplementation (5 µg/mL in food) on lifespan and physiological traits in Drosophila melanogaster under both conventional and axenic (germ-free) conditions. Assays included survival, antioxidant activity, microbial load, and immune gene expression. Aronia berry significantly extended the lifespan of conventional flies but failed to do so in axenic flies, suggesting a microbiota-dependent mechanism. In conventional flies, supplementation of Aronia berry reduced microbial load without altering diversity, enhanced oxidative stress resistance, and upregulated antimicrobial peptide genes via Toll pathway activation. These effects were not observed in axenic flies. Genetic activation of the Toll pathway mimicked the Aronia -induced microbial suppression and lifespan extension, suggesting a causal role for Toll signaling in mediating the health benefits of Aronia berry. Our findings demonstrate that Aronia berry exerts its longevity-promoting effects through commensal microbe-mediated activation of host immunity and oxidative stress reduction. This study highlights the essential role of gut microbes in mediating the health benefits of polyphenol-rich diets and offers insights into dietary strategies for promoting healthy aging.