莲子抗性淀粉对双歧杆菌增殖作用构效关系的研究

According to the traditional Chinese medicine theory, tonifying spleen and benefiting bowel were considered as the function of lotus seed. According to our pre-research, it was found that there was a significant effect on the proliferation of Bifidobacterium (The number of viable cells in added lotus starch medium is 2.03 times that of the glucose control group). Meanwhile, it was also found that resistant starch could form easily after cooking and cooling. Lotus seed resistant starch could be a kind of probiotic, which was likely the reason of the significant effect of lotus seed starch on Bifidobacterium proliferatio. Under this study suggests, we found that there was a significant effect of lotus seed resistant starch on Bifidobacterium proliferation in vitro, which activity was likely related closely to the structure. Therefore the effects of lotus seed resistant starch on proliferation of Bifidobacterium will be studied in this research. By establishing a database of the functional site of Bifidobacterium, effects of lotus seed resistant starch on the functional site of Bidfidobacterium cell synthesis can be determined through fluorescent marker method, and key functional material of lotus seed resistant starch that composed on Bifidobacterium functional sites will be studied. In addition, the structure of lotus seed resistant starch will be analyzed and structure database of lotus seed resistant starch will be established. Moreover, the structure activity relationship between specific structure of lotus seed resistant starch and key functional material, which may effect the proliferation of Bifidobacterium, will be studied and data about probiotic effect of lotus seed resistant starch on Bifidobacterium will also be established. It will provide a theoretical basis for further study of lotus seed resistant starch as a potential probiotic.

传统中医理论认为莲子具有补脾益肠的功效，我们前期研究发现莲子淀粉对双歧杆菌具有显著增殖效应（添加莲子淀粉的培养基其活菌数是葡萄糖的2.03倍），同时发现莲子淀粉经蒸煮冷却后极易形成抗性淀粉，这极有可能是因为莲子淀粉中的抗性淀粉是一种益生元。在此研究提示下，我们研究发现莲子抗性淀粉对双歧杆菌具有显著的体外增殖效应，且其活性可能与其结构密切相关。本课题拟研究莲子抗性淀粉对双歧杆菌的增殖作用，通过建立双歧杆菌作用位点库，采用荧光标记法确定莲子抗性淀粉对双歧杆菌细胞合成的作用位点，进一步研究莲子抗性淀粉在双歧杆菌细胞作用位点上所合成的关键作用物质；同时分析莲子抗性淀粉结构，建立莲子抗性淀粉结构数据库，研究莲子抗性淀粉结构中的特异性结构与其对双歧杆菌增殖的关键作用物质之间的构效关系，构建莲子抗性淀粉促进双歧杆菌生长的益生元效应的数据，为深入研究莲子抗性淀粉潜在益生元功效提供理论基础。

莲子是中医认为“补脾益肠”的食品，我们前期发现莲子淀粉对双歧杆菌具有显著增殖效应，这可能是因为：直链淀粉含量高的莲子淀粉极易形成抗性淀粉，而抗性淀粉是一种益生元。本课题以莲子抗性淀粉为对象，研究了莲子抗性淀粉对双歧杆菌增殖作用的构效关系，主要结果如下：.（1）研究了莲子抗性淀粉对双歧杆菌的体内外增殖作用，结果表明：莲子抗性淀粉能够促进肠道双歧杆菌的体内外增殖，其效果优于高直链玉米淀粉，提高双歧杆菌产短链脂肪酸的能力，尤其是丁酸产量的提高，从而促进机体健康。.（2）分析了莲子抗性淀粉结构及其数据库的构建，结果表明：莲子抗性淀粉偏光十字现象消失，颗粒变为不规则且表面粗糙的块状结构。属于物理变性淀粉，其晶体由C型变为B型，相对结晶度、分子有序排列区域和双螺旋结构含量均高于原淀粉，直链淀粉分子量分布较为集中，聚合度较低。采用醇沉分离出20%醇沉组分和30%醇沉组分，其分子量特征参数：重均分子量Mw分别为8.49×10^4g/mol、 2.23×10^4 g/mol，多分散系数Mw/Mn分别为2.28、1.56。.（3）研究莲子抗性淀粉特异性结构与其对双歧杆菌增殖效应之间的构效关系，结果表明：莲子抗性淀粉及其组分特殊的表面结构、晶体结构以及高双螺旋结构含量可能是双歧杆菌增殖以及增强其对逆环境耐受性的原因；莲子抗性淀粉分子量大小的差异也会影响其促双歧杆菌的增殖作用，分子量较大的莲子抗性淀粉组分的促增殖效应更显著。.综上，莲子抗性淀粉对双歧杆菌具有益生作用，其促双歧杆菌增殖作用与莲子抗性淀粉特殊的表面结构、晶体结构、分子量大小和双螺旋结构含量密切相关，对双歧杆菌具有粘附作用和保护作用。本项研究揭示了莲子抗性淀粉促进双歧杆菌增殖作用的构效关系，为深入研究莲子抗性淀粉的益生元作用及其影响肠道微生态学提供科学依据。