New findings in the metabolism of the saffron apocarotenoids, crocins and crocetin, by the human gut microbiota.

The main constituents of saffron are the apocarotenoids crocins and crocetin, present in the stigmas. Numerous healthy properties, especially those related to the effects on the central nervous system, have been attributed to these compounds but the metabolites responsible for these effects are still unknown. Previous evidences in animal models suggest a role for the gut microbiota in the pharmacokinetics and the neuroprotective effects of these compounds.

Exploring the fate of phlorotannins from Laminaria digitata across the gastrointestinal tract: Insights into susceptibility and bioactivity prior and post gastrointestinal digestion.

Phlorotannins are phenolic compounds exclusive from brown macroalgae endowed with promising bioactive properties. However, considering that diet is their main route of entrance to our system, gastrointestinal digestion might affect such bioactive properties. Here, phlorotannin extracts obtained from Laminaria digitata were submitted to simulated gastrointestinal digestion to evaluate its impact on their antioxidant and anti-inflammatory properties.

NMR Spectroscopic Identification of Urolithin G, a Novel Trihydroxy Urolithin Produced by Human Intestinal Species.

Urolithins are gut microbiota metabolites of ellagic acid. Here, we have identified and chemically characterized a novel urolithin produced from urolithin D (3,4,8,9-tetrahydroxy urolithin) by in vitro incubation with different human gut species under anaerobic conditions. Urolithin G (3,4,8-trihydroxy urolithin) was identified by H NMR, C NMR, UV, HRMS, and 2D NMR.

Gut Bacteria Involved in Ellagic Acid Metabolism To Yield Human Urolithin Metabotypes Revealed.

We aimed to elucidate the gut bacteria that characterize the human urolithin metabotypes A and B (UM-A and UM-B). We report here a new bacterium isolated from the feces of a healthy woman, capable of producing the final metabolites urolithins A and B and different intermediates. Besides, we describe two gut bacterial co-cultures that reproduced the urolithin formation pathways upon in vitro fermentation of both UM-A and UM-B.

Separation of Isomeric Forms of Urolithin Glucuronides Using Supercritical Fluid Chromatography.

Urolithins are gut microbiota metabolites produced in humans after consuming foods containing ellagitannins and ellagic acid. Three urolithin metabotypes have been reported for different individuals depending on the final urolithins produced. After absorption, they are conjugated with glucuronic acid (phase II metabolism), and these are the main circulating metabolites in plasma and reach different tissues.