Molecular Mechanism of Probiotics Group in Maintaining Intestinal HealthHite [4930] Publish time :2017-08-10
The probiotic effect of probiotics has been proved by a large number of animal experiments in the past, but the molecular mechanism of its probiotics does not fully meet the practical application of probiotics. The probabilistic effect of probiotics is not stable. In recent years, a large number of probiotics and intestinal cells, probiotics on pathogens and probiotics on the interaction mechanism of diseases were studied, and some results were achieved. This paper reviews the progress of the above three mechanisms of action.
1 Introduction
The history of human probiotics research is very long. However, the study of products for the intestinal health did not be drilled in until the early 20th century. After the Nobel Prize winner Metchnikoff put forward the concept of probiotics, probiotics are paid much attention to. The research aspects include improving digestive capacity, feeding nutrition, resisting pathogens and bacteria themselves as antibodies and so on. However, most of the researches in the past were in the macroscopic stage, and the probabilistic mechanism of probiotics has not been fully studied, especially in the field of gene activation regulation. At the beginning of the 21st century, with the development of molecular biotechnology, the mechanism of intestinal probiotics was better studied, from in vivo test to in vitro experiments, the interaction between probiotics and intestinal cells mechanism and the role of probiotics on pathogens etc were studied.
Study on the Interaction Mechanism between Probiotics and Intestinal Cells
For intestinal cells, due to the complexity of their composition, the vitro research was in a stage of vitro cultivation technology for a long time. In recent years due to the maturity of intestinal cell cultivation technology, researchers began to study the relationships between intestinal probiotics and a variety of different cells.
2.1 Activating Effect of Probiotics on Intestinal Epithelial Cells
Intestinal epithelial surface area of about 400 square meters, and a long time with a large number of intestinal microbial contact, and intestinal probiotics to maintain contact with the moment, so intestinal epithelial cells is one of the keys to maintain intestinal microecological balance (McCole and Barrett , 2007). For many intestinal diseases, there is growing evidence that intestinal flora has an important role in regulating intestinal immune responses, such as the possibility that certain gene expression programs that recognize specific microbial components can withstand microbial threats (Sansonetti, 2004) , Carotal-related homeodomain protein (Cdx2) and hepatic nuclear factor 1α (HNF1α), etc. (Mitchelmore et al., 2000).
改成：Intestinal epithelial surface is about 400 square meters, coexists with a large number of intestinal microbes and always maintains contact intestinal probiotics, so intestinal epithelial cells is one of the keys to maintain intestinal microecological balance (McCole and Barrett , 2007). For many intestinal diseases, there is growing evidence that intestinal flora plays an important role in regulating intestinal immune responses, such as the possibility that certain gene expression programs can recognize specific microbial components and can withstand microbial threats (Sansonetti, 2004) , Carotal-related homeodomain protein (Cdx2) and hepatic nuclear factor 1α (HNF1α), etc. (Mitchelmore et al., 2000).
Studies have shown that the presence of a mammalian pattern recongition receptors (PRRs) can identify the bacterial and viral structures to activate the proinflammatory metabolic pathways, among which three PRRs are of particular interest. (Toll-like receptors, TLRs); the other is a nucleotide-binding oligomerizetion domain molecules (Nod); and a C-type lectin (C-type lectins, CLRs). TLR, Nod and CLRs all have the ability to recognize bacterial surface proteins, compared with TLR regulation is more obvious. TLRs are usually associated with cell membranes and generally have an exposed leucine repeat recognition domain and an intracellular leukocyte interleukin-0000.
1 receptor, IL-1R) recognition domain, such as TLR4 can recognize Gram-negative bacteria (G-) cell wall lipopolysaccharide (LPS), TLR5 can identify bacteria flagellin (flagellin). And this ability to recognize certain metabolic pathways, such as epithelial cell recognition TLR2 or TLR9 can increase the protective effect of intestinal barrier layer (Cario et al. 2004).