Impact of astaxanthin on the capacity of gut microbiota to produce tryptophan catabolites

and elevated the levels of indole-3-lactic acid and indole-3-propionic acid. These results demonstrated that astaxanthin regulates tryptophan metabolism by modifying gut microbiota and increasing the levels of indole metabolites, such as indole-3-lactic acid and indole-3-propionic acid. This study provides insights into the physiological activity of astaxanthin and sheds light on the potential for enhancing tryptophan metabolism through dietary manipulation of the gut microbiota.