Abstract:Objective: Naturally fermented cow milk is an important part of the daily diet of nomadic people in Tajikistan, which contains rich resources of lactic acid bacteria. However, there are few studies on the microbial community structure and biodiversity of lactic acid bacteria in natural fermented cow milk in Tajikistan. Methods: In this study, pure culture method combined with metagenome sequencing technology was used to study the microbial diversity of naturally fermented cow milk in Tajikistan. At the same time, the microbial community data sets in Tajikistan were compared with another two regions in Kyrgyzstan and Morocco. Result: The results of isolation and identification showed that 92 strains of lactic acid bacteria were isolated from 7 naturally fermented cow milk samples, and the dominant strain was Lactobacillus delbrueckii. The results of sequencing showed that Lactobacillus delbrueckii was the dominant strain with a relative content of 82%. The comparative analysis of the three regions showed that the microbial community in naturally fermented milk had some differences. The composition of bacteria in Tajikistan and Kyrgyzstan was similar, while Morocco was quite different from them. Conclusion: Through this study, we acquired lactic acid bacteria resources and the information of diversity of naturally fermented milk in Tajikistan, provided strains for the development and utilization of lactic acid bacteria, and provided basic data for the research of lactic acid bacteria in naturally fermented dairy products.