Trans-generational effect of sodium benzoate on development and gut microbiota of Drosophila melanogaster

Sodium benzoate (SB) is a widely used synthetic food preservative with broad-spectrum antimicrobial activity. Although generally recognized as safe at regulated levels, concerns persist regarding its potential toxicity at high concentrations. Our previous study demonstrated that chronic exposure to high-dose SB (2000 ppm) significantly delayed pupation and adult emergence timing while altering gut microbiota composition in Drosophila melanogaster. However, whether these developmental and microbial disruptions will be vertically transmitted to the next generation remains unknown. Therefore, in this study, we investigated the trans-generational effects of SB on F1 offspring development and gut microbiota dynamics. Notably, larval pupation and adult emergence time were significantly delayed in offspring derived from SB-exposed parents (2000 ppm). Strikingly, the gut microbiota dysbiosis observed in parental flies was partially attenuated in the F1 generation. However, F1 offspring exhibited significantly higher Shannon and Simpson diversity indices, suggesting a profound restructuring of the microbial community that may reflect over-compensation or an alternative dysbiotic state rather than complete normalization. Gene expression analysis further revealed that while most SB-induced transcriptional changes were normalized in offspring, four key genes, Yp2, TOR, E74B and CAT, remained persistently upregulated, indicating sustained trans-generational dysregulation. Collectively, these findings provide novel evidence that SB exposure can induce trans-generational developmental toxicity, potentially mediated by persistent gene dysregulation despite recovery of the gut microbiota. These findings highlight the need for further mechanistic investigations in future work.