Combined microbiome and metabolomics analysis of yupingfeng san fermented by <i> Bacillus coagulans</i>: insights into probiotic and herbal interactions

In this study, the composition and metabolic profile of yupingfeng san after the fermentation of <i>B. coagulans</i> were studied, and it was found that the fermentation group showed rich species diversity, in which the abundance of Leuconostoc and Weisseria increased significantly, while the opportunistic pathogens such as <i>Pseudomonas aeruginosa</i> and Enterobacter decreased significantly. The analysis of metabolic products showed that the contents of acids, lipids and ketones were significantly increased, rich in a variety of beneficial microorganisms and small molecular compounds with antibacterial effects, and these changes worked together to inhibit the growth of pathogens and maintain intestinal health. The study not only helps to elucidate the assembly mechanism and functional expression of microorganisms after Chinese traditional medicine fermentation, but also provides a solid scientific basis for the development of efficient and safe micro-ecological feed additives.