Metabolic interactions of limosilactobacillus reuteri ZJ625 and ligilactobacillus salivarius ZJ614 in Co-culture: implications for multi-strain probiotics.

Aims: Limosilactobacillus reuteri ZJ625 and Ligilactobacillus salivarius ZJ614 are potential probiotic bacteria. The mechanisms of enhanced benefits by muti-strain probiotics are yet fully understood. We elucidated the influence of co-culturing on the metabolite profiles of L. reuteri ZJ625 and L. salivarius ZJ614 to decipher the impacts of co-culturing on metabolic interactions between the strains.

Methods and results: L. reuteri ZJ625 and L. salivarius ZJ614 were grown in single and co-cultures in defined media. Bacterial cell metabolites were extracted at the mid-stationary growth phase and analysed using two-dimensional gas-column time-of-flight-mass spectrometry (GCxGC- TOFMS). Mass-spectral data was preprocessed and analysed using unsupervised and supervised methods based on the group allocations. A total of 1387 metabolites were identified, with 18.31% significant metabolites (p < 0.05) and 10.17% differential metabolites (p < 0.05, VIP > 1). The differential metabolites identified include arabinofuranose, methyl-galactoside, N-acetyl-glutamic acid, phosphoric acid, and decanoic acid. The metabolites impacted carbohydrate and amino-sugar metabolism.

Conclusion: co-culturing of L. reuteri ZJ625 and L. salivarius ZJ614 influenced the metabolite profiles of the strains and impacted metabolic/biosynthetic pathways, indicating cell-to-cell interactions between the strains.