食物氧化蛋白对小鼠肠道菌群及氧化还原状态的影响

Effect of oxidated food protein on mice gut flora and redox state

目的研究摄食不同方式氧化酪蛋白对小鼠肠道菌群和氧化还原状态的影响。方法分别以H2O2/Cu2+、HClO处理酪蛋白,丙二醛(MDA)处理酪蛋白、大豆蛋白。雄性KM小鼠分为6组:酪蛋白组,H2O2-Cu2+氧化酪蛋白组,HClO氧化酪蛋白组,MDA氧化酪蛋白组,大豆蛋白组和MDA氧化大豆蛋白组,饲喂10周。结果酪蛋白和大豆蛋白经氧化处理后羰基含量显著上升(P<0.05),体外消化率下降。饲喂氧化蛋白饲粮的小鼠结肠内容物乳杆菌数量均显著低于对照组(P<0.05);HClO和MDA氧化酪蛋白组大肠埃希菌、肠球菌数量显著高于对照组(P<0.05),MDA氧化大豆蛋白组大肠埃希菌数量显著高于对照组(P<0.05)。氧化蛋白处理引起小鼠结肠组织MDA上升,其中MDA氧化蛋白处理达显著水平(P<0.05);结肠过氧化氢酶(CAT)活力上升,其中H2O2/Cu2+和MDA氧化蛋白组达显著水平(P<0.05);H2O2/Cu2+氧化酪蛋白处理引起结肠GSH-Px显著升高(P<0.05);氧化蛋白引起结肠总抗氧化能力(T-AOC)下降,其中H2O2/Cu2+、HClO氧化酪蛋白和MDA氧化大豆蛋白处理达显著水平(P<0.05)。蛋白质体外消化率与结肠肠球菌呈负相关(R=-0.81,P=0.051);蛋白羰基含量与结肠乳杆菌呈显著负相关(R=-0.94,P<0.01);大肠埃希菌(R=0.93,P<0.01)和肠球菌(R=0.85,P<0.05)分别与蛋白羰基含量呈正相关。结论氧化后蛋白消化率降低、羰基含量增高,导致肠道乳杆菌减少,大肠埃希菌和肠球菌上升;结肠黏膜脂质过氧化,氧化损伤程度与蛋白氧化处理方式有关。

Objective To study the impact of food oxidated protein on gut flora and redox state. Method Casein and soy protein were oxidized with MDA, H2O2/Cu2＋ and HClO. Mice were divided into 6 groups and treated with casein （controll）, H2O2/Cu2＋, HC10 and MDA oxidated casein, soy protein （control 2） and MDA oxidated soy protein, respectively. Result Protein digestibility decreased and carbonyls increased （P 〈 0.05 ） depending on oxidating manner. Colon lacto- bacillus decreased significantly in oxidated protein treated mice （ P 〈 0.05 ）. Oxidized casein treatment significantly increased Escherichia coli （ P 〈 0.05 ） , and Enterococcus increased significantly only in mice treated by HC10 and MDA oxidated casein （ P 〈 0.05 ）. Colonic MDA was significantly increased in mice treated by both MDA oxidated protein （ P 〈 0.05 ） ; GSH-Px was only significantly increased in mice treated by H2 O2/Cu2＋ oxidated casein （P 〈 0.05 ） ; T-AOC was decreased especially in mice treated by H2O2/Cu2＋, HClO oxidated casein and MDA oxidated soy protein. There were negative correlations between protein digestibility and Enterococcus （ P = 0.051 ）, protein carbonyl and Lactobacillus （ P 〈 0.01 ）, respectively. Protein car- bonyl showed positive correlation with E. coli（ P 〈 0.01 ） and Enterococcus （ P 〈 0.05 ）. Conclusion Oxidation reduced pro- tein digestibility, causing decrease of intestinal Lactobacillus and increase of E. coli and Enterococcous and induced colonic oxi- dation stress depending on the ways of protein oxidation.