益生菌制剂对抗生素诱导腹泻模型小鼠肠道菌群的调节作用

Regulation Effect of Probiotics on the Intestinal Bacteria in Mice with Antibiotic-associated Diarrhea

研究了益生菌制剂对腹泻模型(Antibiotic-Associated Diarrhea,AAD)小鼠肠道菌群的调节作用。BALB/c小鼠随机分为6组,每组8只,灌胃给予氨苄青霉素(22.4 g/kg),建立小鼠腹泻模型,空白组给予等体积生理盐水。模型建立后,阳性组灌胃给予培菲康(8 g/kg)、益生菌制剂低、中、高剂量组(2.5×10^(6)、5×10^(6)、1×10^(7) CFU)给予复合益生菌制剂,模型组和空白组给予等体积生理盐水,连续14 d。观察益生菌制剂对小鼠体质量、稀便率、稀便级和腹泻指数的影响,测定小鼠IgA、IgG水平,肠道屏障功能相关基因表达水平以及肠道菌群组成。结果表明,与模型组相比三个剂量组在给予益生菌第14天时小鼠稀便率、稀便级和腹泻指数显著降低,IgA水平分别提高13.30%、20.25%、25.83%,IgG水平分别提高6.84%、19.81%、29.64%,TLR4基因表达水平下调16.88%、20.78%、40.91%,NF-κB基因表达水平下调24.91%、37.19%、55.79%,肠道双歧杆菌、乳杆菌数量明显增加,产气荚膜梭菌、肠球菌、肠杆菌数量明显减少。综上所述,益生菌制剂通过调节肠道菌群,调节免疫球蛋白水平,发挥改善AAD作用。

The regulatory effects of probiotics on intestinal flora in antibiotic-associated diarrhea(AAD)mice were investigated.BALB/c mice were randomly divided into 6 groups(8 mice per group).The AAD model was established by intragastric administration of ampicillin 22.4 g/kg,and the blank group was given the same volume of normal saline.After the model was successfully established,the positive group was given bifico(8 g/kg),the low-dose,medium-dose and highdose probiotics groups(2.5×10^(6),5×10^(6),1×10^(7) CFU,respectively)were given compound probiotics,and the model group and blank group were given the same volume of normal saline for 14 consecutive days.The effects of probiotics on the body weight,rate of loose stool,grade of loose stool and diarrhea index in mice,and the serum immunoglobulin IgA and IgG levels,the expression levels of the genes related to intestinal barrier function were determined.The results showed that compared with the AAD model group,the loose stool rate,loose stool grade and diarrhea index of mice of the three probiotics groups all decreased significantly,whilst the the serum IgA and IgG levels increased by 13.30%,20.25%,25.83%and 6.84%,19.81%,29.64%,respectively,the expression levels decreased by 16.88%,20.78%and 40.91%,respectively,for TLR4,and by 24.91%,37.19%and 55.79%,respectively,for NF-κB;the number of viable bacteria of intestinal Bifidobacterium and Lactobacillus increased,whilst the number of viable bacteria of Clostridium perfringens,Enterococcus and Enterobacillus decreased.In conclusion,probiotics can ameliorate AAD by regulating intestinal flora and levels of immunoglobulins.