ABSTRACT
Objective To explore the difference in bacterial flora between faeces and mucosa of sigmoid colon,the possible role and significance of microbiota alteration in the genesis of ulcerative colitis (UC).Methods Fusobacterium, Enterococcus, Lactobacillus, Bifidobacterium, Bacteroides and Escherichia were selected as target bacteria colonies.The content of six target bacteria colonies in faeces and mucosa of sigmoid colon of 35 UC patients (20 active UC, and 15 UC in remission) and 20 health controls were detected by real-time fluorescent quantitative polymerase chain reaction (RT-PCR).Two independent samples t-test was performed to compare the differences in bacterial flora between faeces and mucosa of sigmoid colon.Variance analysis was used to compare the differences in bacterial flora among health controls group,active stage group and remission stage group.Results In health control group, the contents of Fusobacterium, Bacteroides, Enterococcus and Lactobacillus in faeces ((10.94 ± 0.29),(12.42±0.39), (8.73±0.84), (9.05±0.35), respectively) were higher than those in the mucosa of sigmoid colon ((9.36±0.66), (9.88±0.82), (7.70±1.17) and (7.96±0.68), respectively, t=9.83, 12.51, 3.20 and 6.35, all P＜0.05).However, the content of Escherichia was lower in faeces than that in the mucosa of sigmoid colon ((8.03±1.02) lg copy/g vs (8.91±0.52) lg copy/g, t=-3.44, P＜0.05).There was no difference in the content of Bifidobacterium between faeces and mucosa of sigmoid colon ((9.54±0.79) lg copy/g vs (9.42±0.98) lg copy/g, P＞0.05).For UC patients, the contents of Fusobacterium, Bacteroides, Enterococcus, Lactobacillus and Bifidobacterium in faeces ((9.62 ±± 1.13),(11.31±0.71), (9.33±0.65), (8.42±0.80) and (8.85±0.73) lg copy/g, respectively) were higher than those in the mucosa of sigmoid colon ((9.00±0.79), (8.80±0.66), (7.46±0.82), (6.82±1.07) and (8.40±0.72) lg copy/g, respectively, t=2.66, 15.28, 10.58, 7.12 and 2.56, all P＜0.05).The content of Escherichia was lower in faeces than that in the mucosa of sigmoid colon ((8.50 ± 0.52) lg copy/g vs (9.26±0.87) lg copy/g, t=-4.45, P＜0.05).Compared with health control group, the content of Fusobacterium, Lactobacillus, Bifidobacterium and Bacteroides ((8.83 ± 0.81), (7.48 ± 1.59), (8.55±0.79) and (11.11±0.88) lg copy/g) all decreased (F=84.45, 14.58, 10.43 and 24.91, all P＜0.05), while the contents of Enterococcus and Escherichia increased ((9.63 ± 0.39) and (8.74 ±0.53) lg copy/g, F=9.87 and 5.55,both P＜0.05).For remission stage group, only the content of Bacteroides decreased ((11.56±0.21) lg copy/g, P＜0.05).Compared with health control group, the contents of Fusobacterium, Bacteroides, Lactobacillus, Bifidobacterium ((8.52 ± 0.30), (8.34 ±0.29), (6.29±0.52) and (8.06±0.21) lg copy/g) all decreased in active stage group (F=16.99,35.98,22.28 and 16.08, all P＜0.05);the content of Escherichia increased ((9.68±0.56) lg copy/g, F=11.19,P＜0.05);there was no difference in the content of Enterococcus ((7.19±0.32) lg copy/g, P＞0.05).In remission stage group, the contents of Bacteroides fragilis and Bifidobacterium decreased ((9.42±0.48) lg copy/g and (8.87±0.89) lg copy/g, both P＜0.05), there was no difference in other bacterias (all P＞0.05).In both faeces and mucosa of sigmoid colon, the ratios of Bifidobacterium and Enterobacteriaceae (B/E value) in active stage group were less than 1 (0.98±0.13 and 0.84±0.05),which significantly decreased compared with health control group (1.21 ± 0.19, 1.06 ± 0.08;F=12.64,76.20, both P＜0.05).In remission stage group, B/E values were higher than 1 both in faeces and mucosa (1.14±0.08 and 1.02±0.04), and there was no difference compared with those of control group (P＞0.05).Conclusions The distribution of target bacteria in feces and sigmoid colonis differed between health controls and UC patients.There are obvious changes in fecal and mucosa associated bacterial flora in UC patients especially in active stage compared with healthy controls.
ABSTRACT
Objective Sigmoid mucosa specimens of the patients with ulcerative colitis ( UC ) at active stage and remission stage were respectively detected by real-time PCR for the contents of the six kinds of bacterial floras inclu-ding fusobacterium, enterococcus, lactobacillus, bifidobacterium, bacteroides, and escherichia coli. So the possi-ble roles and significance of the changes of intestinal mucosa associated bacterial flora in the pathogenesis of UC were discussed. Methods Sigmoid biopsy tissues were collected from 35 UC patients ( 20 cases were activities group while 15 cases were remission group) and 20 healthy cases( control group) . Specific primers were set accord-ing to the bacterial 16 SrDNA sequences. Bacterial DNA of the intestinal mucosa specimens was extracted, and re-al-time PCR was used to detect the numbers of different bacterial colonies. Results In sigmoid mucosa specimens of the UC group at activities group, escherichia coli colony was increased, while bifidobacterium, bacteroides, lac-tobacillus and fusobacterium, were reduced compared to the control group(P0.05). And in remission group, bacteroides and bifidobacterium were reduced com-pared with the control group(P0.05 ) . The ration of bifidobacterium to escherichia coli ( B/E ) in UC pa-tients at active stage was less than 1, which was lower than the control group. While B/E values in UC patients at remission stage and the control group were both larger than 1 , with no statistically significant difference between them. Conclusion There were obvious changes of intestinal bacterial flora in UC patients, and the change is more obvious in the UC patients at active stage, showing that there is a close relationship between intestinal mucosa asso-ciated bacterial flora and the development of UC.