Study On Population Structure Of Oral Microflora And Co-culture Of Probiotics From Intestine

Microorganisms in nature are closely related to human life.Both the long history brewing of vinegar,soy sauce,alcoholic beverages,and moden industrial microbial mining or environmental governance are closely linking with microbes.The development of science and technology and medical diagnosis make people realize that the microorganism in human body is closely related to individual health.The imbalance of human microecology,such as oral microecology and intestinal microecology,may lead to the development of a series of diseases.The community structure of human microorganism is influenced by living environment and living habits.Bioinformatics analysis software QIIME(Quantitative Insights Into Microbial Ecology)and real-time quantitative Reverse Transcription PCR(qRT-PCR)are relatively mature tools and methods for the study of microbial communities.In this experiment,two different aspects of research,oral microbes and probiotics,were performed based on QIIME and RT-PCR respectively.The aims were to explore the relationship between dietary habits and oral microbial community structure,understanding of the potential effects of diet on the health of the human body,as well as research methods to explore the growth characteristics of the growth of probiotics were cultured.The results of probiotics co-culture will be extended to the intestinal microflora,simulating the in vivo environment of probiotic interaction or intestinal microbial interaction to lay the foundation for the study.The main contents are as follows:1.A questionnaire survey was conducted among college students,and saliva samples were collected from 36 subjects who met the requirements of the experiment.The microbial DNA in saliva samples was extracted and sequenced by Illumina.Using Linux server to build QIIME analysis platform and configure analysis environment.A series of bioinformatics analysis was carried out on the sequencing data using QIIME software.The bioinformatics analysis results concluded that:The genus Corynebacterium,Streptococcus and other potential pathogenic strains are positively related to Non-vegetarian food,Peptostreptococcus and Eubacteria were negatively correlated with Non-vegetarian food.2.A total of three probiotics,LGG(Lactobacillus rhamnosus GG),BB12(Bifidobacterium animalis subsp.Lactis Bb-12)and Nissle 1917(Escherichia coli Nissle 1917),were involved in the co-culture experiment of probiotics.Based on the analysis of growth standard curve and growth kinetics curve,the co-culture conditions and the co-culture scheme were established.MacConkey Agar medium was used to screen Nissle 1917 in co-culture system.The pheS gene of LGG as a reference gene,luxS gene of LGG as the experimental gene in RT-PCR experiment.Through co-culture screening experiment of Nissle 1917 strain and co-culture of LGG strain RT-PCR experiment,we can draw a conclusion that:in co-culture,both LGG and BB12 inhibited the growth of Nissle 1917,and the growth inhibition of Nissle 1917 was stronger when LGG and BB12 grew together.When LGG was co-cultured with BB12 or Nissle 1917respectively,both BB12 and Nissle 1917 inhibited LGG growth.However,when the three probiotics were co-cultured together,BB12 and Nissle 1917 would promote LGG growth.The interplay mechanisms in the co-culture of three probiotics required further studies.