A 7-year feed study on the long-term effects of genetically modified maize containing cry1Ab/cry2Aj and EPSPS genes on gut microbiota and metabolite profiles across two generations of cynomolgus macaques

The health implications of genetically modified (GM) crops remain controversial relative to their non-GM counterparts, particularly regarding long-term dietary exposure. Although the gut microbiome is a key health indicator, studies investigating the impact of GM crop consumption on intestinal microbiota remain limited. This study presents a comprehensive 7-year evaluation of GM maize expressing cry1Ab/cry2Aj and G10evo-EPSPS proteins through metagenomic and metabolomic analyses. We assessed the effects of GM maize consumption on gut microbiota diversity and metabolite profiles in cynomolgus macaques (Macaca fascicularis) compared with non-GM maize. Three diet regimens were implemented: a conventional compound feed (CK group), diet formulation containing 70 % non-GM maize (Corn group), and diet formulation containing 70 % GM maize (Tg group). The results demonstrated that feeding GM maize to the first (F0) and second (F1) generations of monkeys did not substantially affect the composition, community structure, or function of the intestinal microbiome, as indicated by species composition and diversity analyses. Minor differences in intestinal metabolites were observed but were not directly linked to transgenic maize consumption. Collectively, long-term intake of maize with cry1Ab/cry2Aj and g10evo-epsps genes had no adverse effects on macaques or their offspring.