【Animal modeling】-Comparative study on the microbial composition of different parts of the digestive tract of wild tree shrew and artificially reared tree shrew

  Objective To use tree shrew as a research model to explore the composition of flora in different intestinal segments of wild tree shrew and artificially bred tree shrew.

  Methods Seven gastrointestinal segment samples of 3 healthy wild and artificially bred tree shrew were collected, and total bacterial DNA was extracted. High-throughput sequencing technology was used to sequence the V3-V4 hypervariable region of the 16S rRNA gene to analyze and compare the structure and diversity of the flora. sex.

  Results The Alpha index diversity analysis of different intestinal segments showed that there were significant differences in the Shannon index in the cecum and stomach between the wild group and the artificial breeding group (P<0.05). There were significant differences in the microbial composition of each intestinal segment between the wild group and the artificial breeding group. At the phylum level, the average proportion of Firmicutes in the four parts of the rectum, colon, cecum and stomach in the wild group was significantly higher than that in the artificial breeding group (P<0.05). ), the average proportion of Spirochaetes in the rectum, colon, cecum and ileum in the artificial breeding group was significantly higher than that in the wild group (P<0.05), and the average proportion of Bacteroidetes in the wild group was significantly higher than that in the artificial breeding group (P<0.05). 0.05), at the genus level, the main bacterial genera in the wild group were significantly higher than those in the artificial breeding group: Weissella in the ileum, jejunum and stomach, Bacteroides in the rectum and Lactococcus in the ileum. The artificial breeding group The main bacterial genera significantly higher than those in the wild group were: Brachyspira in rectum, colon, cecum and ileum, Prevotella_9 in cecum and stomach, Streptococcus in cecum and jejunum, and Lactobacillus in ileum. The functional gene prediction of microbiota in different intestinal segments showed that there were statistically significant differences between the two groups in 17 gene categories in 5 anatomical sites (P<0.05).

  Conclusion Wild tree shrew and artificially bred tree shrew have great differences in the composition of the microbiota in each intestinal segment, and the bacterial function of each intestinal segment is quite different, and it is related to its physiological function and dietary structure. In the study of intestinal microflora, it should be fully considered. Whether the microbial composition of fecal samples is fully representative of the gut microbial composition.