Food Microbial Sciences Unit, School of Food Biosciences, The University of Reading, Reading, UK.
Nutr Res Rev. 2004 Dec;17(2):259-75. doi: 10.1079/NRR200479.
Prebiotics are non-digestible (by the host) food ingredients that have a beneficial effect through their selective metabolism in the intestinal tract. Key to this is the specificity of microbial changes. The present paper reviews the concept in terms of three criteria: (a) resistance to gastric acidity, hydrolysis by mammalian enzymes and gastrointestinal absorption; (b) fermentation by intestinal microflora; (c) selective stimulation of the growth and/or activity of intestinal bacteria associated with health and wellbeing. The conclusion is that prebiotics that currently fulfil these three criteria are fructo-oligosaccharides, galacto-oligosaccharides and lactulose, although promise does exist with several other dietary carbohydrates. Given the range of food vehicles that may be fortified by prebiotics, their ability to confer positive microflora changes and the health aspects that may accrue, it is important that robust technologies to assay functionality are used. This would include a molecular-based approach to determine flora changes. The future use of prebiotics may allow species-level changes in the microbiota, an extrapolation into genera other than the bifidobacteria and lactobacilli, and allow preferential use in disease-prone areas of the body.
益生元是指那些无法被（宿主）消化的食物成分，它们通过在肠道中的选择性代谢而产生有益的影响。关键在于微生物变化的特异性。本文从三个标准来综述这个概念：（a）抵抗胃酸、哺乳动物酶的水解和胃肠道吸收；（b）在肠道微生物群中发酵；（c）选择性刺激与健康和福祉相关的肠道细菌的生长和/或活性。结论是，目前符合这三个标准的益生元是果寡糖、半乳寡糖和乳果糖，尽管其他几种膳食碳水化合物也有希望。鉴于可能通过益生元强化的各种食物载体，它们能够带来积极的微生物群变化以及可能产生的健康方面的影响，因此使用稳健的功能测定技术非常重要。这将包括一种基于分子的方法来确定菌群变化。未来益生元的使用可能会使微生物群发生种水平的变化，不仅限于双歧杆菌和乳杆菌属，还可以优先用于身体易患病的部位。
