益生素和益生元在营养和健康中的新观念

New Concepts of Probiotics and Prebiotics in Nutrition and Health

益生素在预防腹泻、增强乳糖耐受和调节免疫等方面具有很好的功效;益生素还具有预防癌症和降低血清胆固醇的潜力。双歧杆菌和乳酸菌作为2种主要有益菌在改善肠道微生物菌群中起重要作用。非消化性低聚糖即益生元可选择性促进结肠内有益菌生长和增强肠道健康。益生素和益生元在调节胃肠道功能中是最具前景的功能性食品,包括调控食物转运时间、肠道习性、粘膜蠕动性以及表皮细胞增殖;平衡结肠微生物区系,调节营养物质特别是离子的生物学利用率;调控消化道系统的免疫活性和内分泌活性,调节脂代谢。益生素和益生元的混合制品即合生元具有叠加和协作效应,在应用效果上较单独使用益生素或益生元更佳。本文主要综述了益生素、益生元和合生元的概念、生理功能及其应用,并简要讨论了这些功能性食品的安全性及其未来的发展趋势。

Probiotics are the health enhancing functional food ingredients used therapeutically to prevent diarrhea, improve lactose tolerance and modulate immunity. They may also have potential to prevent cancer and lower serum cholesterol levels. Lactobacillus and bifidobacterium play an important role in changing the composition of the gut microbiota. A Prebiotic is defined as a nondigestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of helpful bacterial in the colon and thus improves host health. Probiotics and prebiotics are most promising functional foods, and among the most desirable targets for these functional foods are the gastrointestinal functions, including those that control transit time, bowel habits, and mucosal motility as well as those that modulate epithelial cell proliferation. Desirable targets are also gastrointestinal functions that are associated with a balanced colonic microflora, that are associated with control of nutrient bioavailability （ion in particular）, that modify gastrointestinal immune activity, or that are mediated by the endocrine activity of the gastrointestinal system. Finally, some systemic functions such as lipid homeostasis that are indirectly influenced by nutrient digestion or fermentation represent desirable targets. A synbiotic can be defined as a mixture of probiotics and prebiotics that is being used increasingly to denote a synergistic relationship between viable beneficial bacteria and their selective substrate, and has the potential for enhanced health promotion over probiotics or prebiotics alone. The present review encompasses information regarding the probiotics and prebiotics and their proposed functions. It addresses the concepts and applications of probiotics, prebiotics and synbiotics. Finally, the list of commercially available products are reviewed with brief discussion of questions regarding the reliability, safety and the prospect of these products.