生物被膜：益生菌肠道定植的新策略

益生菌可改善机体微生态平衡，在促进营养吸收、控制肠道感染和调节免疫功能等方面具有特殊的功效，但存在胃肠道环境难定植、口服生物利用度低等问题。生物被膜是多个细菌黏附于非生物或生物表面，分泌胞外聚合物(extracellular polymeric substances)，并将自身包裹其中形成的一种有组织的细菌集团，包含胞外多糖(exopolysaccharides,EPS)、蛋白质、胞外DNA (extracellular deoxyribonucleic acid,eDNA)和脂质等多种组成成分，是一个具有三维立体空间结构的聚集体。被膜状态的益生菌较浮游菌在抗逆性、对抗病原菌和调节免疫功能等方面具有明显优势，这些特点为新型益生菌的开发提供了新的研究思路。本文阐述了被膜状态益生菌的优势，重点介绍了促进益生菌生物被膜形成的活性物及其形成机制，简述了益生菌生物被膜的安全性问题。当前，益生菌生物被膜的研究尚处于起步阶段，希望本文能为该领域未来的研究提供参考。

Bacterial biofilms: novel strategies for intestinal colonization by probiotics

Probiotics can improve the microecological balance of the body and have special effects in promoting nutrient absorption, controlling intestinal infections, and regulating immune function. However, there are problems such as difficult colonization in the gastrointestinal environment and low oral bioavailability. Bacterial biofilms are organized bacterial cells that adhere to an abiotic or biotic surface and are enclosed in extracellular polymeric substances of exopolysaccharides (EPS), extracellular DNA (eDNA), proteins and lipids, with a three-dimensional spatial structure. Probiotics with the help of bacterial biofilms have obvious advantages over planktonic bacteria in stress resistance, combating pathogens and modulating the host''s immune function, which provides a new research idea for the development of probiotics. This paper expounded on the advantages of probiotics with the help of bacterial biofilms, and focused on introducing substances that could promote the formation of probiotic biofilms and the mechanisms, and the safety of probiotic biofilms. Currently, research on probiotic biofilms is still in its infancy, and this paper is expected to provide references for future research in this field.