The mutual interactions of silymarin and colon microbiota

A multi-omics approach was used to investigate interactions among silymarin (seed extract of Silybum marianum), colon microbiota and metabolic profiles. Gut metabolism and microbiota may play a role in the activity of many natural remedies.

Using an in vitro colon model batch incubations with faeces of 20 individuals (10 young adults under 45 years, 10 seniors above 70 years), we explored the effect of age and individuals’ microbial profiles on the catabolism of silymarin (50 μg/mL), and the reverse effect on microbiota. Next-generation sequencing (NGS), liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance spectrometry (¹H-NMR) were used, and the data from all three platforms were processed separately and by data fusion using PERMANOVA, lowest AIC model, linear models, and relevance network analysis.

Silymarin was catabolised into a few final products with m/z 469.113, suggesting demethylation of its main flavonolignans. Silymarin was found to suppress bacterial metabolism, as evidenced by a 2.8% decrease (p<0.01) in the production of short-chain fatty acids (SCFAs), an 8.4% decrease (p<0.001) in branched-chain fatty acids (BCFAs), and decreased utilisation of carbohydrates, and amino acids (p<0.05). No effect on the microbiome composition itself was observed. Differences in the microbial profiles of both age groups were associated with differences in metabolism, with young adults showing more catabolites with m/z=469.113 and m/z 471.129. Clear associations were found between the abundance of Faecalibacterium and other bacterial taxa, and the production of the most abundant transient metabolite with m/z 485.144.

Funding Supported by GA CR, projects 23-04655S and 21-00551S.

Publication History

Article published online:
16 November 2023