Chronic Toxicity of Genetically Modified Maize with Cry1Ab-ma Gene and Its Effect on Serum Metabolites in Rats

Genetic engineering has inserted the crystallin (Cry) gene of Bacillus thuringiensis into the genes of maize to cultivate a variety of transgenic insect-resistant maizes. At present, genetically modified maize with Cry1Ab-ma gene (maize CM8101) was in the stage of safety verification. In this study, a 1-year chronic toxicity test was carried out to evaluate the safety of maize CM8101. Wistar rats were selected for the experiment. Rats were randomly divided into three groups and fed the corresponding diets: genetically modified maize group (CM8101 group), parental maize group (Zheng58 group), and AIN group. Rat serum and urine were collected at the third, sixth, and twelfth months of the experiment, and viscera were collected at the end of the experiment for detection. Metabolomics was used to analyze the metabolites in the serum of rats at the 12th month. While the CM8101 group rats' diets were supplemented with 60% maize CM8101, no obvious poisoning symptoms were found in rats, and no poisoning death occurred. There were no negative effects on body weight, food intake, blood and urine indices, or organ histopathological examination results. Furthermore, metabolomics results revealed that, when compared to group differences, the gender of rats had a more obvious effect on metabolites. The CM8101 group primarily changed linoleic acid metabolism in female rats, while glyceropholipid metabolism was altered in male rats. In rats, consumption of maize CM8101 did not result in significant metabolic dysfunction.