Shumao Cui1,2,3, Cailing Chen1,2, Jiayu Gu1,2, Bingyong Mao1,2, Hao Zhang1,2,3, Jianxin Zhao1,2, Wei Chen1,2,4,5. 1. State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, PR China. 2. School of Food Science and Technology, Jiangnan University, Wuxi, PR China. 3. State Key Laboratory of Dairy Biotechnology, Shanghai Engineering Research Center of Dairy Biotechnology, Dairy Research Institute, Bright Dairy & Food Co. Ltd, Shanghai, PR China. 4. National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, PR China. 5. Beijing Innovation Center of Food Nutrition and Human Health, Beijing Technology and Business University (BTBU), Beijing, PR China.
Abstract
BACKGROUND: Lactobacillus plantarum is an important probiotic with a variety of physiologic functions. Studies have focused on the effects of L. plantarum on host physiology and microbiota, but studies of the fate of strains after they enter the intestine are lacking. In this study, L. plantarum ST-III was genetically engineered to express green fluorescent protein (GFP). Mice were administered ST-III-GFP, and fluorescence imaging was used to study the distribution, location and quantity of strains within 8 h after entry into the intestine. RESULTS: The results indicated that genetic modification did not affect the growth of ST-III, tolerance to simulated gastric juice and intestinal fluid or tolerance to antibiotics (with the exception of chloramphenicol). Fluorescence imaging and colony counting indicated that ST-III-GFP can be detected in the small intestine 5 min after oral gavage. After 30 min, nearly all ST-III-GFP was located in the small intestine. After 1.5 h, ST-III-GFP was detected in both the cecum and large intestine. After 4 and 8 h, ST-III-GFP was mainly concentrated in the cecum and large intestine. Compared to the initial amount ingested, the survival rate of ST-III-GFP within the intestine of mice was 10% after 8 h. In addition, a strong linear relationship was found between the fluorescence intensity and the viable count of ST-III-GFP. CONCLUSIONS: The obtained data indicate that the amount of ST-III-GFP can be estimated by measuring the fluorescence intensity of this novel strain within the intestinal tract.
BACKGROUND:Lactobacillus plantarum is an important probiotic with a variety of physiologic functions. Studies have focused on the effects of L. plantarum on host physiology and microbiota, but studies of the fate of strains after they enter the intestine are lacking. In this study, L. plantarum ST-III was genetically engineered to express green fluorescent protein (GFP). Mice were administered ST-III-GFP, and fluorescence imaging was used to study the distribution, location and quantity of strains within 8 h after entry into the intestine. RESULTS: The results indicated that genetic modification did not affect the growth of ST-III, tolerance to simulated gastric juice and intestinal fluid or tolerance to antibiotics (with the exception of chloramphenicol). Fluorescence imaging and colony counting indicated that ST-III-GFP can be detected in the small intestine 5 min after oral gavage. After 30 min, nearly all ST-III-GFP was located in the small intestine. After 1.5 h, ST-III-GFP was detected in both the cecum and large intestine. After 4 and 8 h, ST-III-GFP was mainly concentrated in the cecum and large intestine. Compared to the initial amount ingested, the survival rate of ST-III-GFP within the intestine of mice was 10% after 8 h. In addition, a strong linear relationship was found between the fluorescence intensity and the viable count of ST-III-GFP. CONCLUSIONS: The obtained data indicate that the amount of ST-III-GFP can be estimated by measuring the fluorescence intensity of this novel strain within the intestinal tract.