The Correlation Research Between Psychological Factors And Dominant Microflora Of Digestive Tract In Both Of South Asian Students And Domestic Students From A University In Yunnan

Objectives In this study,the medical undergraduate students as the research object.Real time fluorescent quantitative PCR method was used to detect the dominant microflora in the digestive tract.To understand the difference of the dominant microflora in the digestive tract between domestic and South Asian students and to study the differences between the oral microflora and the intestinal microflora in the same research object.To explore the influence factors of the dominant microflora in the digestive tract.At the same time,we can figure out the the relationship between psychological factors and the number of dominant microflora in the digestive tract,to improve the quality of study and life of South Asian students in China.It is important to understand the relationship between the dominant microflora in the digestive tract and its influencing factors in order to maintain the balance of intestinal microecosystem.Methods 1.Screening subjects and sampling: According to the strict inclusion and exclusion criteria,select 50 domestic students and 50 South Asian students in a University of the grade 2014 medical undergraduate students.A detailed questionnaire survey included 21-Item Depression Anxiety and Stress Scale,Eysenck Personality Q uestionnaire-Revised and Pittsburgh Sleep Quality Index were conducted among all participants.All research objects were collected the fecal samples and oral swab samples.We extracted the genomic DNA and put the nucleic acid concentrations were 20 ?g/m L.2.Q-PCR standard plasmid preparation: PCR amplification was performed using species primers designed for the 16 S r DNA fragment,the amplified target fragment was connected to plasmid vector and transformed into E.coli.After sequencing and identification of the reserve,the plasmid was quantified and gradient diluted,as the fluorescent quantitative standard,to determine the appropriate concentration and establish the standard curve.3.Quantitative detection o f the dominant microflora in the digestive tract: Detection the content of Total bacteria,Bacteroides,Bifidobacterium,Lactobacillus,Enterococcus and Escherichia coli in fecal samples and oral swab samples of domestic and South Asian students by Q-PCR.4.Data arrangement and analysis: SPSS17.0 statistical software was used to analyze the differences of the dominant microflora in the digestive tract of domestic and South Asian students,and to analyze the relationship between the dominant microflora in the digestive tract and psychological factors.Results 1.Analysis of the questionnaire survey results of the two groups: There was no significant difference in age,sex,BMI,mode of delivery,exercise habit and defecation habit between the two groups(P>0.05).The scores of depression,anxiety and stress in South Asian students were higher than domestic students(P<0.05).And the differences were statistically significant.2.Two groups of intestinal microflora quantitative: In fecal specimens,the number of Total bacteria,Bacteroides,Bifidobacterium and Lactobacillus in South Asian students were less than domestic students(P<0.05).But the number of Escherichia coli and Enterococcus in South Asian students were more than domestic students(P<0.05).All the differences were statistically significant.3.Two groups of oral microflora quantitative: In Oral swab specimens,the number of Bacteroides,Bifidobacterium and Lactobacillus,in South Asian students were less than the domestic students(P<0.05),But the number of Escherichia coli and Enterococcus in South Asian students were more than domestic students(P<0.05).All the differences were statistically significant.4.Comparative analysis of oral microflora and intestinal microflora : The number of Total bacteria,Bacteroides,Bifidobacterium,Lactobacillus and Escherichia coli in oral microflora were less than the intestinal microflora(P<0.05).But the number of Enterococcus in the oral microflora were more than the intestinal microflora(P<0.05).All the differences were statistically significant.5.Analysis the colonization resistance of two groups: The B/E value of intestinal microflora in two groups were high than 1.The colonization resistance of domestic students were more than South Asian students(P<0.05),the difference was statistically significant.6.The correlation between psychological factors and dominant microflora in the digestive tract: In fecal samples the number of Escherichia coli was positively correlated with the scores of depression scale and pressure scale(r = 0.243,P<0.05;r = 0.217,P<0.05).In oral swab samples,the number of Escherichia coli were positively correlated with the scores of depression scale(r = 0.250,P<0.05),the difference were statistically significant.Conclusions 1.In this University,both the domestic and South Asian medical students have good intestinal microecology,but the colonization resistance of domestic students were stronger than South Asian students.2.There were some differences in the number of dominant microflora in the digestive tract between South Asian students and domestic students.The number of Bacteroides,Bifidobacterium and Lactobacillus in South Asian students were less than domestic students,but the number of Escherichia coli and Enterococcus in South Asian students were more than domestic students.3.In this University,the overall mental health of South Asian students well in C hina,but there were still individual students with depression,anxiety and stress symptoms.It is necessary for managers and psychologists to pay more attention on it,and prevent the occurrence of serious psychological problems.4.There is a certain correlation between the number of Escherichia coli in digestive tract and psychological factors,but the specific mechanism needs further study.