Metagenomic analysis of lactic acid bacteria communities in inner Mongolian fermented dairy products: influence of milk source and geography.

Abstract

Inner Mongolia, a key grassland region in China, has a long-standing tradition of fermented dairy products. This study aimed to elucidate the influence of milk source and geographical origin on the community structure and functional characteristics of lactic acid bacteria (LAB) in fermented milk. Twenty-four fermented milk samples from four regions were subjected to metagenomic sequencing analysis including α/β-diversity assessment, taxonomic classification, and functional annotation. The milk source and geographical region jointly shaped the diversity of LAB. The LAB community structure in fermented mare milk displayed more pronounced geographical differentiation than that in fermented cow milk. The core dominant LAB species included Lactobacillus kefiranofaciens, Lactobacillus helveticus, and Lactococcus lactis, with L. helveticus being more abundant in fermented mare milk. The functional profiles of LAB varied depending on the milk source used. The data indicated that milk source was a primary factor associated with the core LAB composition, while geographical origin was associated with the modulation of community diversity and functional attributes. These findings provide region-specific insights into the microbial ecology of traditional Inner Mongolian fermented dairy products.