Growth promotion markers and functional metabolomic analysis of co-cultured Bifidobacterium animalis subsp. lactis HN-3 and Lacticaseibacillus paracasei YL-29 in Elaeagnus moorcroftii Wall.ex Schlecht juice

Co-culturing fermentation can improve the bioactivity and metabolic diversity of bacterial strains. In this study, we explored the cooperation between Bifidobacterium animalis subsp. lactis HN-3 (B.an3) and Lacticaseibacillus paracasei YL-29 (L.cp29) by non-targeted metabolomics and prokaryotic transcriptomics analysis. B.an3 and L.cp29 co-culture showed greater growth than the monoculture fermentation through 7 growth regulating metabolic pathways that facilitated the accumulation of monoculture growth-correlated markers, including, raffinose, stachyose, and  L-thymidine involved in nucleotide and galactose metabolism. On the other hand, compared to the monoculture fermentation, the significantly enhanced functional activities of the co-culture were associated with 74 and 68 significantly altered metabolites, such as phenylacetaldehyde, succinic acid, and trans-cinnamic acid with antioxidant, anti - inflammatory, and anti-bacterial properties. Overall, this study revealed the cooperative beneficial relationship between B.an3 and L.cp29. It offered novel insights into the co-culture mechanisms, providing a basis for further development of microbial natural products.