Cow's milk-based functional foods that can prevent gastroenteritis

进行了以下研究工作：（i）检查牛乳蛋白在体外和体内实验动物感染模型中预防感染的功效，（ii）获得适当的处方，以及（iii）最终生产可以预防胃肠炎的基于牛乳的功能性食品。轮状病毒（HRV）和幽门螺杆菌（Hp）是主要致病菌。获得了以下结果：I.预防HRV感染：体外中和试验显示，<300>通过超滤/渗滤获得的含有乳粘蛋白复合物（MMC）的高Mr乳清蛋白浓缩物（HWPC_）或其来自Sephacryl S-500凝胶过滤的空隙体积分数（FI）在抑制HRV感染方面是高度有效的。此外，一个馏分含有一些低Mr的蛋白质与去污剂从MMC解离被发现是有效的特异性抗体从牛的初乳与HRV（Rotamilk IgG）超免疫。在实验动物感染模型中，明确证明口服HWPCjoo以及Rotamilk IgG可预防乳小鼠由HRV引起的腹泻。HWPC_（300）的最小剂量为10 g/d，Rotamilk IgG的最小剂量为500 mg/d。预防HP感染：在洗涤剂存在下，用Fl及其来自凝胶过滤的级分测试体外抑制Hp尿素酶粘附于胃粘蛋白的能力。与硫酸葡聚糖（DS）相比，F1的IC_<50>（10）低100倍，其乳粘蛋白组分的IC_（10）低1000倍。由于已经报道饲料中的2.5%DS可以预防正常胸腺无毛小鼠中的Hp定殖，因此可以得出结论，Fl及其含乳粘蛋白的级分将能够预防体内Hp感染。

A research work was carried out ( i ) to examine the efficacy of cow's milk proteins to prevent infections both in vitro and in experimental animal infection models in vivo, ( ii ) to obtain proper prescriptions, and ( iii ) finally to produce a cow's milk-based functional food that can prevent gastroenteritis. Human rotavirus ( HRV ) and Helicobacterpylori ( Hp ) were the target causative agents. The following results were obtained.I. Prevention of HRV infection: In vitro neutralization test revealed that the high-Mr whey protein concentrate ( HWPC_<300> ) containing milk mucin complex ( MMC ) obtained by ultra filtration/diafiltration or its void volume fraction ( Fl ) from Sephacryl S-500 gel filtration is highly potent in inhibiting HRV infection. Moreover, a fraction containing some low-Mr proteins dissociated from MMC with detergent was found to be as potent as the specific antibodies from a colostrum of the cow hyperimmunized with HRV ( Rotamilk IgG ). In the experimental animal infection model, it was clearly demonstrated that orally administered HWPCjoo, as well as Rotamilk IgG, prevented diarrhea in suckling mice caused by HRV. A minimum dose of HWPC_(300) in infants may be 10 g a day while 500 mg of Rotamilk IgG may be enough forprevention from diarrhea.II. Prevention of HP infection: The ability to inhibit adherence of Hp urease to gastric mucin in vitro was tested with Fl and its fractions from gel filtration in the presence of detergent. Comparing to the inhibiting activity of dextran sulfate ( DS ), it was demonstrated that IC_<50> of F1 was 〜100 fold lower and those of its fractions containing milk mucin were 〜1000 fold lower than that of DS. Since it was already reported that 2.5 % DS in feed could prevent Hp colonization in euthymic hairless mice, it can be concluded that Fl and its milk mucin containing fractions would be able to prevent infection of Hp in vivo.