Coculture of Collinsella aerofaciens and Bacteroides thetaiotaomicron under bile acid stress reveals vitamin B6 exchange

ABSTRACT: Background: Although the bile acid-mediated microbiome-host interaction is known to shape both the composition and functionality of the gut microbiome, the mechanisms by which bile acid stress influences specific microbial metabolic interactions remain poorly understood. To address this gap, we examine the metabolic interplay between two key gut microbes. Bacteroides thetaiotaomicron, one of the most abundant species, possesses a broad enzymatic repertoire for polysaccharide degradation, while Collinsella aerofaciens is associated with liver-related diseases and plays a role in modifying primary bile acids. Results: In anaerobic coculture, C. aerofaciens mitigated the inhibitory effects of deoxycholic acid (DCA) on B. thetaiotaomicron by absorbing DCA from the medium and partially converting it into glycine-conjugated derivatives. Proteomic analysis showed that DCA broadly disrupted amino acid and vitamin metabolism pathways, particularly in B. thetaiotaomicron. In contrast, coculture led to a general upregulation of these pathways in C. aerofaciens, with a marked activation of vitamin B6 metabolism. Additionally, C. aerofaciens exhibited increased production of citrulline and ornithine in coculture. Conclusions: C. aerofaciens alleviates DCA toxicity on B. thetaiotaomicron through absorption, while promoting amino acid and vitamin metabolism, including the vitamin B6 synthesis pathway, during coculture. These results suggest that microbial interactions can enhance resistance to bile acid stress and may influence gut microbiome resilience, with potential relevance for liver- and bile acid–related disorders.

INSTRUMENT(S):

ORGANISM(S): Collinsella Aerofaciens Atcc 25986 Bacteroides Thetaiotaomicron (strain Atcc 29148 / Dsm 2079 / Nctc 10582 / E50 / Vpi-5482)

SUBMITTER: Yan Wang  

LAB HEAD: Nico Jehmlich

PROVIDER: PXD069395 | Pride | 2026-01-06

REPOSITORIES: Pride