蝇蛆粉对腹泻小鼠肠道大肠杆菌数量及血清抗氧化酶和消化相关酶活性的影响

本试验旨在明确蝇蛆粉作为饲料添加剂对腹泻小鼠肠道大肠杆菌数量及血清抗氧化酶和消化相关酶活性的影响。选取3~4周龄健康雄性昆明种小鼠75只,随机分为5组,每组3个重复,每个重复5只。第1~5天为建模期,模型组、8.0%蝇蛆粉组、5.0%蝇蛆粉组、2.5%蝇蛆粉组腹腔注射0.02 mL/g的3×10^8 CFU/mL的大肠杆菌菌悬液建立腹泻模型,空白组则注射等剂量的无菌生理盐水,造模期间各组均饲喂基础饲粮。第6~15天为治疗期,8.0%蝇蛆粉组、5.0%蝇蛆粉组、2.5%蝇蛆粉组小鼠分别饲喂2 g蝇蛆粉添加剂量为8.0%、5.0%、2.5%的混合饲粮后再自由采食基础饲粮,模型组和空白组小鼠则自由采食基础饲粮。治疗期结束后测定各组腹泻小鼠回肠、盲肠和结肠中大肠杆菌和总菌数量及血清中超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、谷胱甘肽硫转移酶(GST)、乳酸脱氢酶(LDH)、淀粉酶(AMS)、脂肪酶(LPS)的活性。结果显示:模型组小鼠回肠、结肠和盲肠中大肠杆菌数量均显著高于其他各组(P<0.05);8.0%蝇蛆粉组小鼠回肠、盲肠、结肠中大肠杆菌数量与空白组相比均差异不显著(P>0.05),与模型组和2.5%蝇蛆粉组相比均显著降低(P<0.05),同时其结肠中大肠杆菌数量比空白组低17.12×10^4 CFU/mL。腹泻导致小鼠血清中抗氧化酶和消化酶活性均显著降低(P<0.05)。治疗10 d后,8.0%、5.0%和2.5%蝇蛆粉组小鼠血清中SOD、POD、CAT和GST活性均显著高于模型组(P<0.05),且小鼠血清中这4种抗氧化酶活性均随着蝇蛆粉添加剂量的增加而升高,同时8.0%蝇蛆粉组小鼠血清中GST活性显著高于空白组(P<0.05);8.0%和5.0%蝇蛆粉组小鼠血清中LPS、AMS和LDH活性均显著高于模型组(P<0.05),2.5%蝇蛆粉组小鼠血清中LPS和LDH活性也显著高于模型组(P<0.05)。由此可见,蝇蛆粉能降低腹泻小鼠肠道中大肠杆菌和总菌数量,提高血清中抗氧化酶和消化相关酶活性,在添加剂量为8.0%时效果最好。

Effects of Fly Maggot Powder on Intestinal Escherichia coli Count and Serum Antioxidant Enzyme and Digestion-Related Enzyme Activities of Diarrhea Mice

This experiment was conducted to clarify the effects of fly maggot powder as a feed additive on the intestinal Escherichia coli count and the activities of antioxidant enzymes and digestion?related enzymes in ser?um of diarrhea mice.Seventy?five healthy male Kunming mice at 3 to 4 weeks of age were randomly divided into 5 groups with 3 replicates in each group and 5 mice per replicate.On days 1 to 5,the mice in the model group,8.0%,5.0%and 2.5%maggot powder groups were intraperitoneally injected with 0.02 mL/g of 3×10^8 CFU/mL Escherichia coli suspension to establish a diarrhea model,the mice in the blank group was injec?ted with an equal dose of sterile saline,and each group was fed a basic diet during the modeling period.On days 6 to 15,the mice in the 8.0%,5.0%and 2.5%maggot powder groups were fed 2 g mixed diets with fly maggot powder additive dosages of 8.0%,5.0%and 2.5%,respectively,and freely fed a basal diet after mixed diets.Model group and blank group mice freely fed the basal diet.The counts of Escherichia coli and to?tal bacteria in the ileum,cecum and colon and the activities of superoxide dismutase(SOD),peroxidase(POD),catalase(CAT),glutathione S?transferase(GST),lactic dehydrogenase(LDH),amylase(AMS)and lipase(LPS)in serum of diarrhea mice were measured after the end of treatment period.The results showed that the count of Escherichia coli in the ileum,colon and cecum of the model group was significantly higher than that of the other groups(P<0.05).The count of Escherichia coli in the ileum,cecum and colon of the 8.0%fly maggot powder group was not significantly different from that of the blank group(P>0.05),but significantly lower than that of the model group and the 2.5%fly maggot powder group(P<0.05).The count of Escherichia coli in the colon of the 8.0%fly maggot powder group was lower than the blank group of 17.12×10^4 CFU/mL.Diarrhea caused a significant decrease in the activities of antioxidant enzymes and diges?tion?related enzymes in serum of mice.After treatment 10 days,the activities of SOD,POD,CAT and GST in serum of the 8.0%,5.0%and 2.5%fly mottle powder groups were significantly higher than those of the model group(P<0.05),and above four antioxidant enzyme activities in serum of mice increased with the increase of fly maggot powder additive dosage,while the serum GST activity of the 8.0%fly maggot powder group was significantly higher than that of the blank group(P<0.05).The activities of LPS,AMS and LDH in serum of the 8.0%and 5.0%fly maggot powder groups were significantly higher than those of the model group(P<0.05).The activities of LPS and LDH in serum of the 2.5%fly maggot powder group were also significantly higher than those of the model group(P<0.05).It can be seen that fly maggot powder can reduce the counts of Escherichia coli and total bacteria in the intestine of diarrhea mice,increase the activities of antioxidant en?zymes and digestion?related enzymes in serum,and the fly maggot powder additive dosage of 8.0%has the best effect.