溶血性葡萄球菌来源的细胞外囊泡对小鼠生长性能、免疫力、肠道形态与微生物区系的影响

Effects of Staphylococcus haemolyticus -Derived ExtracellularVesicles on Growth Performance, Immunity, IntestinalMorphology and Microbiota of Mice

本试验旨在研究溶血性葡萄球菌来源的细胞外囊泡(SH-EVs)对小鼠生长性能、免疫力、肠道形态与微生物区系的影响。选用体重、日龄接近的20只健康雄性离乳C57BL/6小鼠,采用完全随机试验设计分为2个组,每组10个重复,每个重复1只小鼠。每隔1 d给对照组小鼠灌服150μL磷酸盐缓冲液(PBS),给试验组小鼠灌服150μL SH-EVs悬液(含500μg SH-EVs)。试验期为5 d。结果显示:1)与对照组相比,灌服SH-EVs显著降低了小鼠的平均日采食量和平均日增重(P<0.05),并有提高料重比的趋势(P=0.052)。2)与对照组相比,灌服SH-EVs显著提高了小鼠血清肿瘤坏死因子-α(TNF-α)和白细胞介素-10(IL-10)含量(P<0.05),显著降低了血清免疫球蛋白A(IgA)含量(P<0.05),有降低血清免疫球蛋白G(IgG)含量的趋势(P=0.067)。3)灌服SH-EVs导致小鼠回肠绒毛损伤,肠绒毛稀疏。4)与对照组相比,灌服SH-EVs在门水平上显著降低了小鼠肠道拟杆菌门(Bacteroidetes)的相对丰度(P<0.05),显著提高了酸杆菌门(Acidobacteria)、绿弯菌门(Chloroflexi)、变形菌门(Proteobacteria)、浮霉菌门(Planctomycetes)的相对丰度(P<0.05);在属水平上显著降低了小鼠肠道普雷沃氏菌科UCG-001(Prevotellaceae_UCG-001)、拟杆菌属(Bacteroides)、拟普雷沃菌属(Alloprevotella)的相对丰度(P<0.05);在种水平上显著降低了小鼠肠道产酸拟杆菌(Bacteroides acidifaciens)的相对丰度(P<0.05),显著提高了毛螺菌科细菌COE1(Lachnospiraceae_bacterium_COE1)的相对丰度(P<0.05)。由此可见,灌服SH-EVs降低了小鼠的生长性能、免疫力,一定程度上损伤了肠道形态发育并扰乱了肠道菌群结构,对小鼠健康产生了不利影响。

This experiment was conducted to study the effects of Staphylococcus haemolyticus-derived extracellular vesicles(SH-EVs)on growth performance,immunity,intestinal morphology and microflora of mice.Twenty healthy male C57BL/6 mice with similar body weight and age were randomly assigned into 2 groups with 10 replicates per group and 1 mouse per replicate.Mice in control group were fed 150μL phosphate buffer solution(PBS),and those in test group were fed 150μL SH-EVs suspensions(containing 500μg SH-EVs)every other day.The experiment lasted for 5 days.The results showed as follows:1)compared with the control group,administration of SH-EVs significantly decreased the average daily feed intake(ADFI)and average daily gain(ADG)of mice(P<0.05),and tended to increase the ratio of feed to gain(F/G)(P=0.052).2)Compared with the control group,administration of SH-EVs significantly increased the serum tumor necrosis factor-α(TNF-α)and interleukin-10(IL-10)contents(P<0.05),significantly decreased serum immunoglobulin A(IgA)content(P<0.05),and tended to decrease serum immunoglobulin G(IgG)content(P=0.067).3)Administration of SH-EVs resulted in ileum villi injury and sparse of mice.4)Compared with the control group,administration of SH-EVs significantly reduced the relative abundance of Bacteroidetes in intestine of mice(P<0.05),and significantly increased the relative abundances of Acidobacteria,Chloroflexi,Proteobacteria and Planctomycetes at phylum level(P<0.05);significantly reduced the relative abundances of Prevotellaceae_UCG-001,Bacteroides and Alloprevotella in intestine of mice at genus level(P<0.05);significantly reduced the relative abundance of Bacteroides acidifaciens in intestine of mice(P<0.05),and significantly increased the relative abundance of Lachnospiraceae_bacterium_COE1 at species level(P<0.05).In conclusion,administration of SH-EVs reduces the growth performance and immunity of mice,damages the morphological development of intestine and disturbs the structure of intestinal microflora to a certain extent,and has adverse effects on the health of mice.