Conway P L
School of Microbiology and Immunology, University of New South Wales, Sydney, Australia.
Asia Pac J Clin Nutr. 1996 Mar;5(1):10-4.
Probiotics are preparations of live microorganisms which beneficially affect the host by improving the properties of the indigenous microbes. Since the human intestinal flora plays an important role in health and disease of man, probiotics are used to improve intestinal health and to stimulate the immune system. The microbes commonly used as probiotics for humans are the lactic acid bacteria (LAB). In early studies the strains used for fermenting milk products for human consumption were frequently used as probiotics. Subsequently, it was realised that it would be more appropriate if the strains originated from the human intestinal tract and that in addition to LABs, other microorganisms could be used either singly or in combination. Today, strict selection criteria are employed to obtain functional probiotic strains. It is generally agreed that the strain should be of host origin, well characterised, able to survive the rigours of the digestive tract and possibly colonise, biologically active against the target as well as to be stable and amenable to commercial production and distribution. In addition, information on dosages and evidence of efficacy needs to be obtained. In vitro and in vivo studies are frequently combined to allow investigation of the various parameters, and ultimately clinical trials are required. Although lactic acid bacteria have been generally recognised as safe, the question of safety is discussed for LAB and non-LAB probiotic strains in terms of potential pathogenicity of the strains and risk to the individual and the community. Finally, even though the techniques for genetic manipulation of many probiotic strains are available, it is not envisaged that this issue will be addressed in the near future because of regulatory implications. It is proposed that when this type of selection criteria is employed, probiotics strains with demonstrable efficacy can be obtained.
益生菌是活微生物制剂，通过改善本土微生物的特性对宿主产生有益影响。由于人类肠道菌群在人类健康和疾病中起着重要作用，益生菌被用于改善肠道健康和刺激免疫系统。常用于人类的益生菌微生物是乳酸菌（LAB）。在早期研究中，用于发酵供人类食用的奶制品的菌株经常被用作益生菌。随后，人们意识到如果菌株源自人类肠道会更合适，并且除了乳酸菌外，其他微生物也可以单独使用或组合使用。如今，采用严格的选择标准来获得功能性益生菌菌株。人们普遍认为，该菌株应源自宿主、特征明确、能够在消化道的严苛环境中存活并可能定殖、对目标具有生物活性、稳定且适合商业生产和分销。此外，还需要获得关于剂量和功效证据的信息。体外和体内研究经常结合起来以研究各种参数，最终需要进行临床试验。尽管乳酸菌通常被认为是安全的，但就菌株的潜在致病性以及对个体和群体的风险而言，乳酸菌和非乳酸菌益生菌菌株的安全性问题仍在讨论中。最后，尽管许多益生菌菌株的基因操作技术已经存在，但由于监管方面的影响，预计在不久的将来不会解决这个问题。有人提出，当采用这种类型的选择标准时，可以获得具有可证明功效的益生菌菌株。
