Gut Microbiota Dynamics and Phenotypic Changes Induced by Tetracycline in Drosophila melanogaster

Gut microbiota plays a crucial role in both physiological and pathological processes in humans and animals. Antibiotics, designed to combat bacterial infections, can induce alterations in the composition and abundance of the gut microbiota over prolonged exposure. This study addresses the limited understanding of the connections between gut microbiota and phenotypic profiles of metazoan species. We investigated the impact of early-life exposure to tetracycline in wild-type D. melanogaster, which were fed a standard diet, comparing them to a control group not exposed to tetracycline. The primary objective was to examine the consequences of early-life tetracycline exposure on gut microbiota and its implications for phenotypic profiles, including survival, locomotor activity, and reproduction in adult flies. Results revealed a significant reduction in lactic acid bacteria in adult flies exposed to tetracycline. However, tetracycline exhibited no interference with fly development, allowing them to maintain a normal lifespan. In adult flies, tetracycline significantly decreased the lifespan on day 35 at a concentration of 1000 µg/mL and reduced locomotion on day 27 at concentrations of 10 µg/mL and 1000 µg/mL. Remarkably, tetracycline did not impact the reproductive capabilities of the flies. This study demonstrates that while tetracycline led to a decline in lactic acid bacteria, locomotion, and lifespan in adult flies, it did not disrupt their development or reproductive processes.