Interplay between herbal medicine and intestinal bacteria: interaction of willow bark extract and human intestinal microbiota in vitro

Herbal preparations are complex mixtures of natural products, many of which are able to reach the distal gut where they influence the microbial community on the one hand, and can be metabolized into potentially bioactive metabolites by intestinal bacteria on the other hand. The aim of this study was to establish a platform for investigating the interactions of herbal medicinal products and intestinal microbiota by using a combined LC-MS metabolomics and microbiomics approach. As an example, we used willow bark extract (WBE), a herbal medicinal product with well-established anti-inflammatory activity. The extract was incubated with human fecal suspension (HFS) under anoxic conditions, and samples were drawn after 0.5, 4 and 24 h of anoxic incubation.