The hydrogenation metabolism process of rosmarinic acid by microbial enzymes in chickens

BACKGROUND: The gut microbiota plays a critical role in the metabolism of rosmarinic acid (RA) through converting RA to caffeic acid (CA), danshensu (DSS), and m-coumaric acid. However, the gut environment and microbiota may have complicated metabolic converting RA processes. This study aimed to investigate the metabolism of RA in gastrointestinal tract of chickens through liquid chromatography-tandem mass spectrometry (LC-MS/MS) and metagenomic analysis. RESULTS: Through in vivo and in vitro studies, RA was found to be hydrogenated into dihydrorosmarinic acid, then hydrolyzed into DSS and dihydrocaffeic acid (DHCA). DSS and DHCA could be further converted to 3-hydroxyphenylpropionic acid. But RA remained stable in the stomach, duodenum, jejunum, and ileum, as well as in the cecum of antibiotic-treated chickens. This indicated that the degradation of RA was mainly mediated by cecal microbiota. Furthermore, the metagenomic analysis of cecal microbiota revealed that reductases and hydrolases from Clostridium spp., Alistipes spp., and other microbiota were involved in these processes. NADH:flavin oxidoreductase and 3-oxoacyl-[acyl-carrier-protein] reductase participated in the hydrogenation reaction of RA, and BaiCD involved in dehydroxylation reaction of RA. CONCLUSION: The hydrogenation process by microbial enzymes was an important metabolic pathway of RA. These hydrogenation products contribute to improving the biological function of RA. © 2025 Society of Chemical Industry.