Selective metabolism of tormentil rhizome constituents by human gut microbiota and its impact on biodiversity ex vivo

Tormentil rhizome was used for centuries in traditional medicine to treat gastrointestinal disorders. Its anti-inflammatory, antioxidant, and antibacterial properties, and unique taste, suggest its potential as a food additive for functional foods. The research aimed to determine gut metabolites of the extract, their impact on microbiota biodiversity, and interactions between them. Gut metabolites were obtained by ex vivo incubation of extract with fecal samples. Among the compounds, only catechin and its oligomers were metabolized by gut microbiota. Triterpenes remained unchanged, while ellagic acid derivatives were undetected in metabolized and unmetabolized forms. The extract also promoted bacteria growth from the Ruminococcaceae family (producers of short-chain fatty acids) and other families, increasing microbiota biodiversity. A mutual interaction occurred between Ruminococcaceae and metabolites, with bacteria influencing metabolite production and metabolites enhancing bacterial growth. The selective metabolism of tormentil rhizome and its interaction with gut microbiota may offer new strategies to improve gut health.