Title Page

Contents

Abstract 8

INTRODUCTION 10

METHODS 12

1. Study participants 12

2. Study design 13

3. 16S rRNA Gene Sequencing 15

4. Diversity indices and Statistical analysis 15

RESULTS 16

1. Baseline characteristics 16

2. Changes of overall microbial composition and diversity between V1 and V2 19

3. Differences in the Specific taxa 21

4. Clinical characteristics of patients according to beta-diversity change 22

DISCUSSION 26

References 31

논문요약 36

Table 1. Baseline characteristics of all CD patients. 17

Table 2. Specific taxa with statistically significant changes between V1 and V2. 21

Table 3. Clinical characteristics of three groups according to degree of beta-diversity change 24

Figure 1. Schedules of fecal sampling 14

Figure 2. Microbial changes of overall composition between V1 and V2. 20

Figure 3. Categorization into three groups according to beta-diversity change. 23