Composition of the bacterial community in the gastrointestinal tract of Kunming mice

Background: The intestinal bacterial community has an important role in maintaining human health. Dysbiosis is a key inducer of many chronic diseases including obesity and diabetes. Kunming mice are frequently used as a model of human disease and yet little is known about the bacterial microbiome resident to the gastrointestinal tract. Results: We undertook metagenomic sequencing of the luminal contents of the stomach, duodenum, jejunum, ileum, cecum, colon, and rectum of Kunming mice. Firmicutes was the dominant bacterial phylum of each intestinal tract and Lactobacillus the dominant genus. However, the bacterial composition differed among the seven intestinal tracts of Kunming mice. Compared with the small intestine, the large intestine bacterial community of Kunming mice is more stable and diverse. Conclusions: To our knowledge, ours is the first study to systematically describe the gastrointestinal bacterial composition of Kunming mice. Our findings provide a better understanding of the bacterial composition of Kunming mice and serves as a foundation for the study of precision medicine.

Use of green fluorescent protein to monitor Lactobacillus plantarum in the gastrointestinal tract of goats

The experiment aimed to specifically monitor the passage of lactobacilli in vivo after oral administration. The green fluorescent protein (GFP) gene was cloned downstream from the constitutive p32 promoter from L. lactis subsp. cremoris Wg2. The recombinant expression vector, pLEM415-gfp-p32, was electroporated into Lactobacillus plantarum (L. plantarum) isolated from goat. Green fluorescent protein (GFP) was successfully expressed in L. plantarum. After 2 h post-administration, transformed Lactobacillus could be detectable in all luminal contents. In the rumen, bacteria concentration initially decreased, reached the minimum at 42 h post-oral administration and then increased. However, this concentration decreased constantly in the duodenum. This result indicated that L. plantarum could colonize in the rumen but not in the duodenum.