Introduction/Background: Genetically modified crops have been available for human and animal consumption since the 1990’s ². Most crops have been modified to possess genes that either make them herbicide tolerant or insect resistant. Increasingly common though, are crops that possess both traits¹. Second to soy, corn is the most widely grown GM crop in the world¹. In spite of the increased popularity of GM crops, very few studies have been done to assess the long-term effects of GM food on mammals. The aim of the present study was to investigate the long-term effects of feeding rats corn containing modifications for both insect resistance and herbicide tolerance.
Methodology: Twenty Sprague Dawley rats were fed a diet containing either GM corn or non-GM corn for 23 weeks. The GM corn was a triple stacked corn containing modifications for insect resistance (MON810 and MON863) and herbicide tolerance (NK603). Stomach mucosa was examined using routine light and transmission electron microscopy.
Results: There was no inflammation present in the stomach mucosa of any of the rats. However, light microscopy examination revealed large/medium gland dilatations present in GM fed animals. Necrotic tissue was seen in some of the abnormal glands, as well as flattened lining cells and epithelial dysplasia. Transmission electron microscopy revealed a number of poorly apposed tight junctions between mucous producing cells in GM fed rats.
Conclusion: Results show that feeding rats a GM corn diet affects stomach mucosa morphology as well as tight junctions at the mucosal surface. This suggests that the mucosal barrier of the stomach has been compromised, which may lead to serious health complications.