益生菌功能开发及其应用性能强化

Functional development and performance enhancement of probiotics

随着人们居住环境、饮食习惯和生活节奏的改变,许多新型疾病开始出现并严重威胁着人类健康.在"大健康"理念及其产业化背景下,人们的健康意识逐渐提升,而益生菌凭借其优良的益生性能受到了越来越广泛的关注.益生菌(probiotics)指可有效增强食用者身体健康水平的活菌制剂及其代谢产物,具有改善便秘、缓解腹泻、降胆固醇、增强免疫力、预防和治疗自闭及抑郁症,抗肿瘤和保护口腔健康等功效,其主要产品益生菌膳食补充剂和益生菌非处方药等已在医药领域得到广泛应用.随着对益生菌与疾病关系研究的不断深入,益生菌在新型及重大疾病防治领域的新功能不断刷新着人类的认知.因此,学术界需进一步加强益生菌的基础研究,开发益生菌在疾病防治领域的新功能.同时,在益生菌产品的制备和应用过程中,多种严峻的环境胁迫会影响菌株正常的代谢和存活能力,抑制其益生作用的发挥.因此,利用多种手段,对其应用性能进行强化显得尤为重要.本文综述了益生菌功能开发和性能强化的主要方法和原理,概括了其在多种疾病防治过程中的应用效果,为加深对益生菌功能的认识,进一步促进益生菌产业升级提供了可借鉴的思路.

Several new kinds of diseases posing serious threat to human life have developed owing to the drastic changes in living environment, eating habits, and lifestyle. Concomitantly, there has been a gradual increase in health awareness among people, and probiotics have gained much attention for its excellent health benefits. Probiotics are live microorganisms, mainly bacteria such as Lactobacillus, Lactococcus, Bifidobacterium, Leuconostoc, and Streptococcus, which benefit human health, especially the digestive system. Probiotics have been reported to improve constipation, reduce diarrhea, decrease the content of cholesterol, enhance immunity, and protect oral health. Moreover, they have been associated with anti-tumor effects and positive effects towards prevention and treatment of autism and depression. Currently, probiotics dietary supplements and non-prescription drugs are widely used in the field of medicine. With the gradual improvement in research tools, newer functions of probiotics and insights into its relationship with diseases continue to emerge. Thus, it is important to further engage in the basic research of probiotics and explore new functions in the field of disease prevention. Meanwhile, inevitably, probiotics production faces a variety of stresses from the external environment, such as acid stress caused by lactic acid accumulation in the fermentation process, freezing stress during formulation, and osmotic stresses at various production stages. These adverse conditions affect the normal metabolism and survival of strains, thus inhibiting their probiotic effects. Therefore, it is essential to improve the stress tolerance of strains and strengthen the performance of probiotics. Recent developments in biotechnology, including microbial community analysis and high throughput screening, and evolutionary techniques can improve the efficiency of strain screening. Evolutionary engineering, including mutagenesis techniques, adaptive laboratory evolution, and genome evolution, is a valuable method to promote the phenotype or physiological characteristics of strains. Moreover, using systems biology, we can examine the effects of mutant strains as probiotics and even apply inverse metabolic engineering approaches to improve microbial characteristics and get the desired phenotype. This comprehensive review describes the main methods and principles used in functional development and performance enhancement of probiotics, and summarizes their effects in the prevention and treatment of various diseases. The aim of this review is to provide an understanding of the multiple functions of probiotics and provide a perspective on the challenges faced in the probiotics industry so as to trigger development of better industrial processes for probiotics production.