Lactobacillus quorum sensing system is an important regulatory pathway for lactic acid bacteria to respond to environmental changes and regulate the expression of related genes in vivo.In order to study the quorum sensing system of lactic acid bacteria,In this study, AI-2 was detected in 8 strains of lactic acid bacteria, and 7 strains of lactic acid bacteria were detected in the AI-2 signal molecules, and 3 of them produce AI-2 signal is very strong.For strains with high yield AI-2,the expression ofluxSgene andLDHgene of lactic acid bacteria were detected by RT-PCR. The expression of luxS gene was higher in lactic acid bacteria with high yield of AI-2, and the expression ofLDHgene was weaker.Finally, the correlation between acid environment and AI-2 production of lactic acid bacteria was analyzed. The results showed that the stronger the acidity of the culture medium, the stronger the AI-2 signal.LuxS gene is the key gene of AI-2 signal synthesis. AI-2 signal molecule improves the acid resistance of lactic acid bacteria, which is beneficial to the lactic acid bacteria to regulate the acid-base balance and flora balance in the intestine through the group induction signal.This study lays the foundation for actic acid bacteria population induction signaling pathway, to explore the lactic acid bacteria in the host intestinal adhesion colonization the mechanism of subsequent analysis.