Antibiotic pretreatment on the efficacy of Clostridium butyricum in the treatment of dextran sulfate sodium induced colitis and the influence of intestinal microbiota / 中华消化杂志

ABSTRACT

Objective:To investigate the effects of Clostridium butyricum on colitis and intestinal microbiota in mice with or without antibiotic pretreatment. Methods:Thirty specific pathogen free BALB/c mice were randomly divided into the blank control group, dextran sulfate sodium (DSS) group, antibiotic + DSS group, Clostridium butyricum + DSS group and antibiotic+ Clostridium butyricum + DSS group, with 6 mice in each group. After the mice were pretreated with quadruple antibiotics (ampicillin 1 g/L, neomycin 1 g/L, metronidazole 1 g/L, and vancomycin 0.5 g/L) in normal drinking water for 30 d, the mice colitis model was induced with DSS. At the same time, the mice in Clostridium butyricum + DSS group and antibiotics+ Clostridium butyricum + DSS group were given 1×10 6colony-forming unit (CFU) Clostridium butyricum by gavage. The effect of Clostridium butyricum on mice with colitis was evaluated by disease activity index (DAI), colon length and histopathological score. The level of serum inflammatory factors was detected by enxyme linked immunosorbent assay, and the effect of Clostridium butyricum on gut microbita in mice was determined by fecal 16S rRNA sequencing. Results:The general condition of mice of the blank control group were good, and their DAI scores fluctuated around 0. Since the fourth day after DSS drinking water was given, the mice of the DSS group showed signs of colitis such as weight loss, unformed stools and bloody stools. On the fourth day after intervention, the DAI score of Clostridium butyricum + DSS group was lower than that of DSS group (0.000±0.000 vs. 0.444±0.111), and the difference was statistically significant ( t=4.000, P=0.016 1). On the tenth and twelfth day after the intervention, the DAI scores of antibiotic+ Clostridium butyricum + DSS group were both lower than those of antibiotic+ DSS group (0.000±0.000 vs. 1.111±0.222, 0.667±0.000 vs. 1.889±0.222), and the differences were statistically significant ( t=5.000 and 5.500, both P<0.05). The histopathological score of mice colon tissue of Clostridium butyricum + DSS group was lower than that of DSS group (2.50±1.73 vs. 5.50±1.00), and the histopathological score of mice colon tissue of antibiotic+ Clostridium butyricum+ DSS group was lower than that of antibiotic+ DSS group (1.25±0.96 vs. 5.00±0.82), and the differences were statistically significant ( t=3.000 and 5.960, both P<0.05). The serum level of interleukin (IL)-1β Clostridium butyricum+ DSS group was higher than that of blank control group ((4.464±0.075) ng/L vs. (3.907±0.080) ng/L), the serum levels of tumor necrosis factor-α, IL-6 and IL-1β of Clostridium butyricum+ DSS group and antibiotic+ Clostridium butyricum + DSS group were all lower than those of DSS group ((2.402±0.383) ng/L , (1.845±0.345) ng/L vs. (6.958±1.084) ng/L, (1.752±0.146) ng/L, (1.307±0.048) ng/L vs. (3.537±0.608) ng/L, (4.464±0.075) ng/L, (4.066±0.190) ng/L vs. (7.477±0.339) ng/L), and the differences were statistically significant ( t=5.005, 3.964, 4.495, 4.693, 6.294, 8.674 and 8.774 , all P<0.05). The results of 16S rRNA sequencing showed that there were a significantly large number of anti-inflammatory or short-chain fatty acid producing bacteria in the gut microbiota of mice intervened by Clostridium butyricum, among which the dominant bacteria genus in Clostridium butyricum + DSS group and antibiotic+ Colstridium butyicum+ DSS group were Mucispirillum (linear discriminant analysis (LDA)=3.667 log10, P=0.004) and Stenotrophomonas (LDA=2.778 log10, P=0.044). In the antibiotic+ Clostridium butyricum+ DSS group, the dominant bacteria genus were Peptococcus (LDA=2.685 log10, P=0.018), Butyricimonas (LDA=2.712 log10, P=0.011), Bilophila (LDA=3.204 log10, P=0.014), Intestinimonas (LDA=3.346 log10, P=0.010), Candidatus- Saccharimonas (LDA=3.363 log10, P=0.029), Desulfovibrio (LDA=3.402 log10, P=0.025), Oscillibacter (LDA=2.870 log10, P=0.019) and Akkermansia (LDA=4.031 log10, P=0.005). Conclusions:Clostridium butyricum can effectively improve colitis in mice and regulate the intestinal microbial structure of mice, whlie antibiotic pretreatment can strengthen its regulation of intestinal microbiota to and enhance the efficacy of Clostridium butyricum.