Adjustment Effect Of Lactobacillus Acidophilus On Disordered Intestinal Microbiota Of Mouce Introduced By Antibiotics

The most direct and frequent complication of long time using broad-spectrum antibiotic is alteration of intestinal flora, and furthermore result in diarrhea and intestinal infection, antibiotic-associated diarrhea has been widespread phenomenon in clinic. Currently probiotic, as new therapeutic tool, has been widely used to treat urgent and chronic diarrhea induced by disorderd intestinal microbe, its purpose is to recover and stabilize the previous microbial balance. But probiotic which mainly aims at disorderd intestinal microbe induced by antibiotic lack and research report disagree."BIFIDO"is a newtype probiotic, which is composed of lactobacillus acidophilus, bifidobacterium and fecal streptococci. Among it lactobacillus acidophilus were demonstrated its superordinary performances in related study such as acidproof, cholateproof and adhering. But there is no report about the regulation function to disordered intestinal flora introduced by antibiotic.There are massive microbe in the intestinal of human and animal, these microbe shape complicated microbiota and keep dynamic balance. Traditional cultivation technique is insufficient to study intestinal microbiota because it only analyse the culturable microbe. So additional techniques are requisite to appraise the regulation function to disordered intestinal microbiota introduced by antibiotic. Denaturing gradient gel electrophoresis (DGGE) targeting 16S rRNA- encoding genes was developed as rapid methodologies with high throughput that are more suitable for analysis of complex microbial communities. DGGE method has been used in intestinal microbiota related study.In this study, lactobacillus acidophilus as objective strain was separated from one probiotic product, after establishing animal model of disorderd intestinal flora by large dose antibiotic ceftriaxone treatment on SPF BALB/c mice for continual five days, investigated and analyzed the regulation effect of objective strain to disorderd intestinal flora by PCR-DGGE and traditional cultivation methods.Results:(一) Animal model establishing of disorderd intestinal flora: after large dose antibiotic ceftriaxone treatment for five days, the dynamic balance of intestinal bacterial populations was broken and the lactobacilli,bifidobacterium,enterobacteriaceae and enterococci numbers decreased markedly, these bacteria numbers can not return to normal level in a week after stoping using antibiotic. Compared with normal control, there was extreme significant difference (p<0.01), animal model was established successfully.(二)The regulation effect of objective strain to disorderd intestinal flora: In therapic group, the lactobacilli, bifidobacterium, enterobacteriaceae numbers increased obviously, but abnormally proliferative enterococci decreased, Compared with spontaneous recovery group, there was extreme significant difference (p<0.01). Similarity analyzation demonstrated that the DGGE banding profiles in each group have similarity in some extent and gather together. In bacterial diversity analyzation, compared with spontaneous recovery group, there was extreme significant difference (p<0.01). At the same time, body weight and ingestion quantity of mice in therapic group are bigger than that of mice in spontaneous recovery group. So experiment results confirmed that the separated objective strain has regulation effect to disorderd intestinal flora introduced by antibiotic, and the corresponding probiotic product is potential to expand its indication.