卫生研究

目的 探究深度水解蛋白奶粉对小鼠的致敏作用。方法 5周龄雌性BALB/c小鼠按体重随机分为4组(n=20):空白对照组、过敏模型组、完整蛋白配方奶粉组、深度水解蛋白配方奶粉组。空白对照组灌胃溶剂，过敏模型组灌胃20 mg β-乳球蛋白，奶粉组分别灌胃173.9 mg完整蛋白配方奶粉和169.5 mg深度水解蛋白配方奶粉，两组配方奶粉剂量按等效蛋白含量匹配；同时，各组均同步给予10μg霍乱毒素(作为黏膜佐剂，能够打破肠道黏膜免疫耐受，增强过敏原的致敏效果)。受试物均以0.2 mol/L NaHCO₃配制，涡旋混匀，现配现用。每周灌胃1次，每次灌胃0.3 mL。实验第29天，每组一半小鼠(n=10)摘眼球取血检测血清β-乳球蛋白特异性IgE。第35天，剩余小鼠(n=10)腹腔注射5 mg β-乳球蛋白，监测激发前后直肠温度变化及过敏症状，取脾计算脾脏系数，收集结肠内容物检测肠道菌群。结果 激发后过敏模型组和完整蛋白组小鼠直肠温度降低(P<0.05),过敏症状评分(1.5分)更高。完整蛋白组血清特异性IgE水平高于深度水解蛋白组(P<0.05)。深度水解蛋白组肠道菌群Richness指数高于完整蛋白组(P<0.05)。完整蛋白组厚壁菌门丰度低于深度水解蛋白组(P<0.05),而拟杆菌门丰度升高(P<0.05)。完整蛋白组GGB46150＿SGB63918、Heminiphilus＿faecis、GGB29545＿SGB42337丰度高于空白对照组(P<0.05),而Alistipes＿sp＿DSM＿112343、Helicobacter＿ganmani丰度降低(P<0.05)。拟杆菌门、GGB27792＿SGB40208和GGB46150＿SGB63918丰度与血清IgE水平正相关(P<0.05);厚壁菌门、Lachnospiraceae＿bacterium和GGB28886＿SGB41567丰度与血清IgE水平，候选美拉那细菌门丰度与过敏症状评分，柔膜菌门、GGB27792＿SGB40208丰度与脾脏系数均负相关(P<0.05)。结论 深度水解蛋白可以降低奶粉的致敏性。

OBJECTIVE Investigating the sensitizing effects of extensively hydrolyzed protein infant formula on mice to provide evidence for the research and clinical application of infant formula.METHODS Female BALB/c mice aged 5 weeks were randomly divided into 4 groups(n=20) by body weight: the blank control group, the positive control group, the extensively hydrolyzed group, and the unhydrolyzed group. All mice were given intragastric administration once a week. On the 29th day of the experiment, half of the mice in each group were subjected to eyeball enucleation for blood(serum) collection to detect specific IgE. On the 35th day, the remaining mice were intraperitoneally injected with 5 mg of β-lactoglobulin for challenge. Subsequently, the changes in rectal temperature and allergic symptoms were monitored; the spleens were harvested to calculate the spleen index; and the colonic contents were collected for gut microbiota detection.RESULTS After challenge, the rectal temperature of mice in the positive control group and the unhydrolyzed group decreased significantly(P<0.05), with higher allergic symptom scores; additionally, the spleen index of the positive control group increased significantly(P<0.05). The serum-specific IgE levels of mice showed a sequential decreasing trend among the unhydrolyzed group, positive control group, blank control group, and extensively hydrolyzed protein group, with significant differences observed between all groups(P<0.05). The Richness index of the extensively hydrolyzed protein group was significantly higher than that of the positive control group and the unhydrolyzed group(P<0.05). Firmicutes in the positive control group and the unhydrolyzed group was significantly lower than that in the blank control group and the extensively hydrolyzed protein group(P<0.05), while Bacteroidetes was significantly increased(P<0.05). In the unhydrolyzed group, GGB46150＿SGB63918, Heminiphilus faecis, and GGB29545＿SGB42337 were significantly higher than those in the blank control group(P<0.05), whereas Alistipes sp. DSM＿112343 and Helicobacter ganmani were significantly decreased(P<0.05). Furthermore, Bacteroidetes, GGB27792＿SGB40208, and GGB46150＿SGB63918 were positively correlated with serum-specific IgE levels(P<0.05). In contrast, Firmicutes and Lachnospiraceae bacterium was negatively correlated with serum-specific IgE levels; Candidatus＿Melainabacteria was negatively correlated with allergy symptom scores; and Tenericutes and GGB27792＿SGB40208 was negatively correlated with the spleen index(P<0.05).CONCLUSION Extensively hydrolyzed proteins can reduce the allergenicity of infant formula, providing a scientific evidence for preventing protein allergies in formula.