We divided three groups. (total number = 60 subjects)~a large number of defecation group (≥ 2-3 times/day) - 20 subjects~normal defecation group (1 time/day or 1 time/2 days) - 20 subjects~a small number of defecation group (≤ 2 times/week) - 20 subjects~After collection of stools, we will analyze the composition and distribution of gut microbiota, and compared the results of three groups.
We hypothesized that some difference in the composition and distribution of gut microbiota in people with a large number of defecation (two or three times a day or more), people with normal defecation (one time a day or two days), and people with a small number of defecation (two times a week or less).~And we investigate the association between gut microbiota and stool frequency.