University of Granada, Department of Applied Physics, Campus de Fuentenueva, Spain.
Adv Colloid Interface Sci. 2011 Jun 9;165(1):36-46. doi: 10.1016/j.cis.2010.12.002. Epub 2010 Dec 15.
Bile salts (BS) are bio-surfactants present in the gastrointestinal tract (GIT) that play a crucial role in the digestion and absorption of nutrients. The importance of BS for controlled release and transport of lipid soluble nutrients and drugs has recently stimulated scientific interest in these physiological compounds. BS are so-called facial amphiphiles showing a molecular structure that is very distinct from classical surfactants. This peculiar molecular structure facilitates the formation of dynamic aggregates able to solubilise and transport lipid soluble compounds. The detergent nature of BS has been studied in the literature, mostly concentrating on the self-assembly behaviour of BS in solution but also in relation to protein denaturation and its effect on improving proteolysis. In contrast, the affinity of BS for hydrophobic phases has received less attention and studies dealing directly with the interfacial behaviour of BS are very limited in the literature. This is despite the fact that the interfacial activity of BS plays a vital role in fat digestion since it is closely involved with lypolisis. BS adsorb onto fat droplets and can remove other materials such as proteins, emulsifiers and lipolysis products from the lipid surface. The unusual surface behaviour of BS is directly related to their intriguing molecular structure and further knowledge could provide an improved understanding of lipid digestion. This review aims to combine the new insights gained into the surface properties of BS and their role in digestion. A better understanding of surface activity of BS would allow manipulation of physico-chemical and interfacial properties to modulate lipid digestion, improve bioavailability of lipid soluble nutrients and reduce absorption of saturated fats, cholesterol and trans fats.
胆汁盐（BS）是存在于胃肠道（GIT）中的生物表面活性剂，在营养物质的消化和吸收中起着至关重要的作用。BS 对脂溶性营养素和药物的控制释放和输送的重要性最近激发了科学界对这些生理化合物的兴趣。BS 是所谓的面状两亲物，其分子结构与经典表面活性剂非常不同。这种特殊的分子结构有助于形成能够溶解和输送脂溶性化合物的动态聚集体。BS 的去污性质在文献中已经进行了研究，主要集中在 BS 在溶液中的自组装行为，但也与蛋白质变性及其对改善蛋白水解的影响有关。相比之下，BS 对疏水性相的亲和力受到的关注较少，文献中直接涉及 BS 界面行为的研究非常有限。尽管事实上 BS 的界面活性在脂肪消化中起着至关重要的作用，因为它与脂肪酶解密切相关，但事实仍然如此。BS 吸附在脂肪滴上，并可以从脂质表面去除其他物质，如蛋白质、乳化剂和脂肪酶解产物。BS 的异常表面行为与其引人入胜的分子结构直接相关，进一步的知识可以提供对脂质消化的更好理解。本综述旨在结合对 BS 的表面性质及其在消化中的作用的新见解。更好地了解 BS 的表面活性将允许操纵物理化学和界面特性，以调节脂肪消化，提高脂溶性营养素的生物利用度，并减少饱和脂肪、胆固醇和反式脂肪的吸收。
