抗生素处理对高脂饲料诱导肥胖SD大鼠肠道菌群与血清炎性因子的影响

CHANGES OF INTESTINAL FLORA AND INFLAMMATORY FACTORS AFTER ANTIBIOTIC TREATMENT IN HIGH-FAT DIET FED SD RATS

目的探讨抗生素处理和高脂饲料喂养对肠道菌群结构改变与炎症反应的影响。方法将44只大鼠分为基础饲养组(n=14)和高脂饲养组(n=30),利用高脂饮食诱导建立肥胖大鼠模型,8 w后根据营养性肥胖大鼠判定标准筛选,将两组大鼠随机分为抗生素干预组和生理盐水对照组(n=7),后进行2 w抗生素(10g/L庆大霉素+10g/L甲硝唑)干预。动物处死剥离内脏脂肪称重并计算脂体比;采集血清检测炎症细胞因子水平;粪便细菌总DNA提取;利用16S rDNA测序技术分析肠道菌群的群落构成及多样性。结果肥胖组(obesity prone,OP)[n=7,高脂饲料+生理盐水]和肥胖组加抗生素干预组(obesityprone-K,OP-K)[n=7,高脂饲料+抗生素(10g/L庆大霉素+10g/L甲硝唑)],大鼠体重、肾周脂肪和附睾脂肪水平均显著高于普通组(control,CON)[n=7,基础饲料+生理盐水]和普通组加抗生素干预组(control-K,CON-K)[n=7,基础饲料+抗生素(10g/L庆大霉素+10g/L甲硝唑)]大鼠,OP组大鼠脂体比明显高于CON组大鼠;与CON组比较,CON-K、OP和OP-K组大鼠体内均发生不同程度炎症反应,且OP-K组大鼠血清IL-1β浓度显著低于OP组;各组大鼠肠道菌群构成在门水平和属水平均表现出不同,肠道内优势菌属发生明显改变;对大鼠的肠道优势菌属和血清炎症细胞因子相关性分析结果显示:Lactobacillus、Lachnospiraceae;K4A136、Ruminococcace-ae;CG;14、Ruminococcaceae;nclassified、Lachnospiraceae;ncultured和Ruminococcaceae;CG;05与IL-4呈正相关关系(P<0.05),Allobaculum和Bifidobacterium与IL-4呈负相关关系(P<0.05),Bacteroides与IL-1β呈正相关关系(P<0.05),Prevotellaceae;K3B31;roup与IL-10呈正相关关系(P<0.05)。结论肥胖及抗生素干预均会导致肠道微生态环境失衡,并诱发机体的炎症反应,肠道菌群与炎症存在一定的必然联系。

Objective To explore the correlation between the structural composition changes of intestinal flora and inflammatory response after antibiotic treatment and high-fat diet feeding in SD rats.Methods Forty-four rats were divided into one group(14 rats)with routine feeding and another group(30 rats)with high-fat diet feeding.The obese rat model was induced by high-fat diet.The rats in the two groups were randomly divided into an antibiotic intervention group(10 g/L gentamicin+10 g/L metronidazole for two weeks)and a normal saline control group(7 rats)according to the criteria for nutritional obesity after eight weeks.After the animals were sacrificed,the visceral fat was stripped and weighed and the fat body ratio was calculated;the serum was collected to detect the level of inflammatory cytokines;the total DNA of fecal bacteria was extracted;16 S rDNA sequencing technology was used to analyze the composition and diversity of the intestinal flora.Results The body weight,perirenal fat and epididymal fat levels in obesity prone(OP)and obesity prone-K(OP-K)groups were significantly higher than those in control(CON)and control-K(CON-K)groups,and the fat body ratio in OP group was significantly higher than that in CON group;Compared with CON group,different degrees inflammatory response appear in CON-K,OP and OP-K groups,and the concentration of serum IL-1βin OP-K group was significantly lower than that in OP group.The composition of intestinal flora of rats in each group was different at the phylum level and the genus level,and the dominant intestinal flora were changed significantly.The results of correlation analysis between dominant intestinal flora and serum inflammatory cytokines showed that Lactobacillus,Lachnospiraceae_NK4 A136,Ruminococcace-ae_UCG_014,Ruminococcaceae_unclassifie,Lachnospiraceae_uncultured and Ruminococcaceae_UCG_005 were positively correlated with IL-4(P<0.05),while Allobaculum and Bifidobacterium were negatively correlated with IL-4(P<0.05),and Bacteroides were positively correlated with IL-1β(P<0.05).Prevotellaceae_NK3 B31_group and IL-10 showed a positive correlation(P<0.05).Conclusion Obesity and antibiotic treatment cause an imbalance of the intestinal flora and induce inflammatory response.There is a certain correlation between the intestinal flora and inflammation.