Safety assessment of genetically modified rice expressing human serum albumin from urine metabonomics and fecal bacterial profile

- Genetically modified rice expresses the pharmaceutical protein human serum albumin.
- Urine and feces were used to conduct food safety assessment.
- The GM rice diet is as safe as the traditional daily diet.
- Fecal bacterial profile has a better potential to be used to predict the change of blood indexes.
- A non-invasive food safety assessment model of genetically modified crops for non-food/feed purposes was developed in rats.

The genetically modified (GM) rice expressing human serum albumin (HSA) is used for non-food purposes; however, its food safety assessment should be conducted due to the probability of accidental mixture with conventional food. In this research, Sprague Dawley rats were fed diets containing 50% (wt/wt) GM rice expressing HSA or non-GM rice for 90 days. Urine metabolites were detected by 1H NMR to examine the changes of the metabolites in the dynamic process of metabolism. Fecal bacterial profiles were detected by denaturing gradient gel electrophoresis to reflect intestinal health. Additionally, short chain fatty acids and fecal enzymes were investigated. The results showed that compared with rats fed the non-GM rice, some significant differences were observed in rats fed with the GM rice; however, these changes were not significantly different from the control diet group. Additionally, the gut microbiota was associated with blood indexes and urine metabolites. In conclusion, the GM rice diet is as safe as the traditional daily diet. Furthermore, urine metabonomics and fecal bacterial profiles provide a non-invasive food safety assessment rat model for genetically modified crops that are used for non-food/feed purposes. Fecal bacterial profiles have the potential for predicting the change of blood indexes in future.