The Diversity Analysis Of Lactobacilli In Different Part Of SD Rat’s Digestive Tract

Purpose:To analyze the diversity of lactobacilli in different part of SD rat’s digestive tractMethod:feed three normal SD rats of6-week-old for four weeks, then sample the mucus or ccontent from the feed, stomach, the proximal small intestine, the distal small intestine and large intestine respectively, extracting DNA of bacterium by the way of PCR-RFLP to analyze the diversity of lactobacilli in different part of SD rat.Results:(1)After the PCR amplification of DNA from the normal feed and four parts of rat, the electrophoresis shows that band exits not in normal feed but in other samples.(2) From three part of the variable region of16S rDNA gene library of the stomach,9equal OTUs(Gene sequence similarity greater than98%) are obtained respectively,6OTUs are cultured lactobacillus strain while other three are uncultured bacterium clone.(3)From three part of the region of16S rDNA gene library of the proximal small intestine,10,9and10OTUs are obtained respectively. The10OTUs from sample1and3are equal, but sample2has less Uncultured Lactobacillus sp. Clone BR15AD06than sample1and3.(4)From three part of the region of16S rDNA gene library of of the distal small intestine,13,12, and13OTUs are obtained respectively. The13OTUs from sample1and3are equal, but sample2has less Lactobacillus johnsonii CRL1452than sample1and3.(5) From three part of the region of16S rDNA gene library of the large intestine,10,11and9OTUs are obtained respectively. Sample1has less uncultured bacterium clone PF4980, and sample3has less uncultured bacterium clone ECN343eO7and Lactobacillus intestinalis TH4.Conclusion:(1) Lactobacillus can be detected in the contents and mucus of stomach,the proximal small intestine, the distal small intestine and large intestine.(2)The diversity of Lactobacilli is highest in the distal small intestine and the evenness is highest in the proximal small intestine, while the diversity and evenness of lactobacilli are lowest in stomach.