Abstract: Objective To investigate the changes in fecal flora and its correlation with the occurrence and progression of
inflammatory bowel disease (IBD). Methods We collected fresh fecal specimens from 167 IBD patients (including 113 with
ulcerative colitis and 54 with Crohn’s disease) and 54 healthy volunteers. The fecal flora was analyzed by gradient dilution
method and the data of inflammatory markers including WBC, PLT, CRP and ESR were collected to assess the association
between the fecal flora and the inflammatory markers. Results The species Enterrococcus (6.60 ± 0.23, P<0.01), Saccharomyces
(2.22 ± 0.27, P<0.05), Bacteriodes (5.57 ± 0.28, P<0.001), Bifidobacterium (5.08 ± 0.30, P<0.01), Peptococcus (6.22 ± 0.25, P<0.001),
Lactobacillus (6.00±0.26, P<0.001), and Clostridium (3.57±0.30, P<0.05) all increased significantly, while Eubacterium (1.56±0.24, P<
0.01) reduced markedly in patients with ulcerative colitis compared with those in the control subjects. Enterrococcus (6.93±0.28,
P<0.01), Saccharomyces (2.73±0.37, P<0.01), Bacteriodes (4.32±0.52, P<0.05), Bifidobacterium (4.88±0.42, P<0.05), Peptococcus (6.19±
0.32, P<0.01) and Lactobacillus (4.73±0.47, P<0.001) all increased significantly and Eubacterium (1.01±0.29, P<0.01) and Clostridium
(0.87±0.31, P<0.01) decreased in patients with Crohn’s disease. The positivity rates of bacterial culture were consistent with the
results of quantitative analysis of the fecal flora. The changes in fecal flora did not show a significant correlation with these
inflammatory markers. Conclusion IBD patients have fecal flora imbalance compared with the healthy controls, and this
imbalance may contribute to the occurrence and progression of IBD. The decline of Eubacterium contributes to the occurrence
and development of IBD.