The effect of genetically modified Lactobacillus plantarum 590 on the gut health of Sprague-Dawley rats

Lp was a generally recognized as safe microorganism. Lactobacillus plantarum 590 was obtained by inserting nisI gene into Lp genome to help it tolerate higher concentration nisin. As the unintended effects of the genetically modified microorganism (GMM) are the most important barriers to the progress of GMM, we have performed a useful exploration to establish a new in vivo evaluation model for GMM from the point of view of intestinal health. In this study, Sprague-Dawley rats were orally administered with Lp 590 and Lp for 4 weeks. Fecal samples were collected to determine the number of beneficial bacteria Bifidobacterium and harmful bacteria Clostridium perfringens. Denaturing gradient gel electrophoresis was used to detect the bacterial profiles of every group. Fecal enzyme activities and short-chain fatty acids as main metabolites were also examined. Real time PCR (RT-PCR) and immunohistochemistry were used to analyze two proteins (ZO-1 and occludin) and secretory immunoglobulin A to detect intestinal permeability and mucosal immunity, gut permeability and gut mucosal immunity were analyzed to see whether GM Lp 590 can induce changes of the gut health when compared with non-GM Lp group, andeventually we concluded that there is no significant difference between GM Lp 590-fed group and non-GM Lp-fed group. The conclusion of gut health test was comparable withthat from traditional subchronic test. Evaluation of intestinal health will be a new approach of assessing the safety of GMM.