益生菌、合生元对急性结肠炎小鼠肠道炎症及菌群的影响

The influence of probiotics and synbiotics on intestinal inflammation and microbiota in mice with acute colitis

目的探讨益生菌、合生元对急性结肠炎小鼠肠道炎症及菌群的影响。方法将C57BL/6J小鼠分为4组,每组10只,A组为空白对照组,B组、C组、D组使用葡聚糖硫酸钠(DSS)诱导结肠炎模型,B组不予灌胃干预(建模对照组),C组、D组分别予益生菌、合生元灌胃。其中,益生菌由嗜酸乳杆菌、鼠李糖乳杆菌、乳双歧杆菌组成;合生元由上述益生菌及菊粉、低聚半乳糖组成。收集灌胃前、灌胃4 d后、灌胃1周后的粪便及处死后的黏膜标本送检,进行16S rDNA基因测序。结果(1)建模对照组、益生菌组、合生元组病理评分分别为27.00±7.94、5.40±2.79、7.25±2.87。与建模对照组相比,益生菌组、合生元组小鼠的结肠炎症程度较轻,病理评分更低(P=0.000 1、0.000 3)。(2)与空白对照组相比,建模对照组、益生菌组、合生元组菌群多样性明显下降,拟杆菌属增加,Faecalibacterium减少。(3)各组的黏膜菌群与粪便菌群相比,菌群丰度与种类均有很大差异,黏膜标本中Mucispirillum丰度均明显高于粪便菌群。结论(1)益生菌、合生元能够降低急性结肠炎小鼠的结肠炎症程度。(2)急性结肠炎小鼠较空白对照小鼠结肠的有益菌属减少、有害菌属增加,而补充益生菌、合生元有利于增加有益菌属比例,调节肠道菌群平衡。

Objective To investigate the effects of probiotics and synbiotics on inflammation and microbiota of acute colitis in mice. Methods C57BL/6J mice were divided into 4 groups randomly. Each group had 10 mice and was given 2.5% dextran sulfate sodium (DSS) drinking water for 5 days other than the blank control group. Except for model control group, other two groups were administrated with probiotics and synbiotics, respectively. Probiotics was composed of Lactobacillus acidophilus, Lactobacillus rhamnosus and Bifidobacterium lactis, while synbiotics was composed of the aforementioned probiotics, inulin and galactooligosaccharide. Feces of different periods and mucosa samples were collected to analyze the differences of enteric flora by 16s rDNA sequencing. Results (1) Pathological scores in probiotics group and synbiotics group were 5.40±2.79 and 7.25±2.87, respectively, which were significantly lower than those in the model control group with scores 27.00±7.94. Model control group, probiotics group and synbiotics group showed lower flora diversity, increased Bacteroides and decreased Faecalibacterium than blank control group. The mucosal microbiota was different from fecal flora in abundance and species for each group, and Mucispirillum was more common in mucosa. Conclusions Probiotics and synbiotics alleviate the inflammation of acute colitis in mice. Imbalance of beneficial genera to harmful genera is the characteristic of acute colitis. Supplementation of probiotics and synbiotics contributes to regulating the balance of intestinal microbiota.