中国现代医学杂志2026，Vol.36Issue(3)：32-43,12.DOI:10.3969/j.issn.1005-8982.2026.03.006
联合抗生素对伪无菌模型大鼠的肠道菌群及其代谢的影响
The effect of combined antibiotics on the intestinal flora and its metabolism in the construction of a pseudo germ-free rat model
摘要
Abstract
Objective To compare the effects of combined antibiotics administered via gavage and free drinking water to establish a pseudo germ-free(PGF)model in SD rats,and to provide a reference for the optimisation of the construction method of the PGF model.Methods SD rats were randomly divided into 3 groups of 5 rats each:normal group(Group N),antibiotic gavage group(Group I)and antibiotic drinking water group(Group D).Group I was treated with a suspension containing 200 mg/mL ampicillin,200 mg/mL metronidazole,200 mg/mL neomycin,and 100 mg/mL vancomycin by daily gavage at a rate of 1 mL/kg volume;In group D,0.5 g/L ampicillin,0.5 g/L metronidazole,0.5 g/L neomycin and 0.25 g/L vancomycin were added to sterilised drinking water and rats were given free access to water for 14 d of the intervention.On the 5th,10th and 14th days after the intervention,feces of the rats were aseptically taken for bacterial colony culture;after 14 days,rat faeces were taken for 16S ribosomal rDNA(16S rDNA)sequencing;liver,spleen,kidney and thymus were isolated and weighed,and colon tissue was taken for HE and immunohistochemical staining.Results Compared with group N,under aerobic and anaerobic culture conditions,the fecal colonies in groups I and D significantly decreased from day 5.The PGF rat model was established and stably maintained until day 14.However,compared with group N,the body weight of group D significantly decreased from day 2 to day 6(both P<0.05),and the difference in weight from day 7 to 14 was not statistically significant(P>0.05);the weight of the group I was higher than that of the group N on day 6(P<0.05).Comparison of liver,kidney,spleen and thymus coefficients of rats in group N,group I and group D showed no statistically significant difference(P>0.05).Alpha diversity analysis based on 16S rDNA sequencing showed that ACE,Sobs and Shannon indices were decreased(P<0.05)and Simpson indices were increased(P<0.05)in the group I and group D compared with the group N;Simpson indices in the group D were increased(P<0.05)compared with that in the group I.Beta diversity analysis based on Bray-Curtis distance showed that the samples from the normal group were significantly separated from the samples from the group I and group D(ANOSIM similarity analysis:r=0.816,P=0.001);Samples from the group I and group D were clustered closer together,indicating a higher degree of similarity in bacterial flora composition between the two groups.The abundance of Proteobacteria was higher in the group I and group D than in the group N(both P<0.05),and the difference between the group I and group D was not statistically significant(P>0.05);the abundance of Firmicutes,Bacteroidetes and Actinomycetes was higher in the normal group than in the group I and group D(all P<0.05).The abundance of Morganella spp.was higher in the group D than in the group I and the group N(both P<0.05);the abundance of Escherichia-Shigella spp.was higher in the group I than in the group D and the group N(both P<0.05);the abundance of Lactobacillus spp.,Bacteroides spp.and norank_f__Muribaculaceae spp.in the group N was higher than in the group I and group D(both P<0.05).KEGG-based functional prediction analyses of the bacterial colonies showed statistically significant differences(P<0.05)in the overall comparison of predicted abundance among the three groups in a number of pathways,including carbohydrate metabolism,amino acid metabolism,energy metabolism,terpene and polyketide metabolism,cofactors,and vitamin metabolism.Conclusion Combined antibiotics administered by gavage and free drinking water were effective in replicating the PGF rat in SD rats within 14 d.However,abnormal multiplication of conditionally pathogenic bacteria occurred in both the group I and the group D,which suggests that antibiotic interventions may change the colony structure through screening pressure,so that potentially pathogenic bacteria,which would otherwise be at a low abundance,may gain a growth advantage.This provides a reference for researchers to replicate the PGF rat model by selecting appropriate antibiotic administration strategies according to the experimental target flora.关键词
16s rDNA测序/伪无菌大鼠/肠道屏障/闭锁小带蛋白-1/闭合蛋白/抗生素联合使用Key words
16S rDNA sequencing/pseudo germ-free rats/intestinal barrier/ZO-1/Occludin/antibiotic combination分类
医药卫生引用本文复制引用
贺莉,颜家朝,喻京生..联合抗生素对伪无菌模型大鼠的肠道菌群及其代谢的影响[J].中国现代医学杂志,2026,36(3):32-43,12.基金项目
国家自然科学基金面上项目(No:8227150650) （No:8227150650）
湖南省自然科学基金面上项目(No:2022JJ30460) （No:2022JJ30460）
