Biotransformation of food spice curcumin by gut bacterium Bacillus megaterium DCMB-002 and its pharmacological implications

Abstract

The food additive curcumin shows many benefits for human health but has low solubility and stability, which leads to its low bioavailability. After oral administration, curcumin undergoes biotransformation by gut microbiota in digestive tracts, and thus it is interesting to characterize the biotransformation products of curcumin and assess their bioactivities to help us understand the pharmacology. Herein a bacterial strain of Bacillus megaterium DCMB-002 isolated from mice feces, showed the capability of transforming curcumin to its various derivatives. The tracing high performance liquid chromatogram coupled with quadrupole time-of-flight tandem mass spectra (HPLC-Q-TOF MS ⁿ ) led to the identification of seven hydrogenation transformation metabolites through reduction, hydroxylation, demethylation and demethoxylation etc, six of which were reported for the first time. The metabolites exhibited moderate antioxidant activity. The findings provided insights into the microbial biotransformation of curcumin and roles of gut microbiota in its pharmacological effects.