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.

Effect of Storage Conditions on the Stability of Polyphenols of Apple and Strawberry Purees Produced at Industrial Scale by Different Processing Techniques.

During a food product's life, storage conditions affect its composition of nutrients, bioactive compounds, and sensory attributes. In this research, strawberry and apple purees were selected as a model to examine how the storage of various purees industrially produced with different technologies affect the bioactive phenolic compounds, color, and sensory attributes. Specifically, fruit products processed on an industrial scale by different technologies including freezing, thermal treatment (mild and standard), and high-pressure processing were studied, as well as storage for up to 12 months at -20, 4, and 24 °C.

Synthesis and Characterization of a Novel Resveratrol Xylobioside Obtained Using a Mutagenic Variant of a GH10 Endoxylanase.

Resveratrol is a natural polyphenol with antioxidant activity and numerous health benefits. However, in vivo application of this compound is still a challenge due to its poor aqueous solubility and rapid metabolism, which leads to an extremely low bioavailability in the target tissues. In this work, rXynSOS-E236G glycosynthase, designed from a GH10 endoxylanase of the fungus was used to glycosylate resveratrol by using xylobiosyl-fluoride as a sugar donor.

Saffron against Neuro-Cognitive Disorders: An Overview of Its Main Bioactive Compounds, Their Metabolic Fate and Potential Mechanisms of Neurological Protection.

Saffron ( L.) is a spice used worldwide as a colouring and flavouring agent. Saffron is also a source of multiple bioactive constituents with potential health benefits.

Untargeted Metabolomics Reveals New Markers of Food Processing for Strawberry and Apple Purees.

In general, food processing and its conditions affect nutrients, bioactive compounds, and sensory characteristics of food products. This research aims to use a non-targeted metabolomics approach based on UPLC-ESI-QTOF-MS to determine how fruit processing can affect the metabolic profile of fruits and, through a comprehensive metabolic analysis, identify possible markers to assess their degree of processing. The present study uses a real case from the food industry to evaluate markers of the processing of strawberry and apple purees industrially elaborated with different processing techniques and conditions.

A novel combined analytical UV and MS approach for the quantification of oleuropein metabolites in human biological samples when authentic standards are not available.

The beneficial health effects of phytochemicals depend on their bioavailability and the form under which they reach systemic circulation, usually as phase II metabolites. The lack of authentic standards for these metabolites makes their quantification in biological samples challenging. A new analytical approach to get a more accurate quantification of oleuropein metabolites in biological samples after ingestion of olive leaf extract was proposed.

Stability of phenolic compounds in apple and strawberry: Effect of different processing techniques in industrial set up.

Different technologies commonly employed by the fruit processing industry affect the phenolic content. This study aimed to establish the extent to which different processing techniques and conditions, tested at an industrial scale, affect phenolics, color, and sensory attributes of fresh strawberries and apples. The effects of freezing, thermal treatments, and high-pressure processing were investigated.

Ellagitannins, urolithins, and neuroprotection: Human evidence and the possible link to the gut microbiota.

Ellagitannins (ETs) and ellagic acid (EA) are dietary polyphenols poorly absorbed but extensively metabolized by the human gut microbiota to produce different urolithins (Uros). Depending on the individuals' microbial signatures, ETs metabolism can yield the Uro metabotypes A, B, or 0, potentially impacting human health after consuming ETs. Human evidence points to improved brain health after consuming ET-rich foods, mainly pomegranate juices and extracts containing punicalagin, punicalin, and different EA-derivatives.

Novel Regioselective Synthesis of Urolithin Glucuronides─Human Gut Microbiota Cometabolites of Ellagitannins and Ellagic Acid.

Urolithins (dibenzo-pyran-[,]-6 one derivatives) are human gut microbiota metabolites produced from the natural food antioxidant ellagic acid. Urolithins are better absorbed than ellagic acid and demonstrate biological activities that suggest that they are responsible for the health effects observed after consuming ellagitannin- and ellagic acid-containing foods. Urolithins occur in the systemic circulation as glucuronide conjugates following phase II metabolism.

Technological and Biotechnological Processes To Enhance the Bioavailability of Dietary (Poly)phenols in Humans.

The health effects of (poly)phenols (PPs) depend upon their bioavailability that, in general, is very low and shows a high interindividual variability. The low bioavailability of PPs is mainly attributed to their low absorption in the upper gastrointestinal tract as a result of their low water solubility, their presence in foods as polymers or in glycosylated forms, and their tight bond to food matrices. Although many studies have investigated how technological and biotechnological processes affect the phenolic composition of fruits and vegetables, limited information exists regarding their effects on PP bioavailability in humans.

Urolithins: a Comprehensive Update on their Metabolism, Bioactivity, and Associated Gut Microbiota.

Urolithins, metabolites produced by the gut microbiota from the polyphenols ellagitannins and ellagic acid, are discovered by the research group in humans almost 20 years ago. Pioneering research suggests urolithins as pleiotropic bioactive contributors to explain the health benefits after consuming ellagitannin-rich sources (pomegranates, walnuts, strawberries, etc.).

High-Pressure Processing vs. Thermal Treatment: Effect on the Stability of Polyphenols in Strawberry and Apple Products.

Polyphenols are important bioactive compounds that are affected by processing. The consumer's demand for minimally processed products contributes to the increase in non-thermal technologies such as high-pressure processing (HPP) in the food industry. This review is aimed at critically discussing the positive and negative effects of thermal treatment (TT) and HPP on the stability of different polyphenol families in agro-food products obtained from strawberry and apple, two of the most used fruits in food processing.

Endocrine disruption in Crohn's disease: Bisphenol A enhances systemic inflammatory response in patients with gut barrier translocation of dysbiotic microbiota products.

The relevance of environmental triggers in Crohn's disease remains poorly explored, despite the well-known association between industrialization and disease onset/progression. We have aimed at evaluating the influence of endocrine disrupting chemicals in CD patients. We performed a prospective observational study on consecutive patients diagnosed of CD.

Urolithins in Human Breast Milk after Walnut Intake and Kinetics of Colonization in Newly Born: The Role of Mothers' Urolithin Metabotypes.

The maternal-infant transmission of several urolithins through breast milk and the gut colonization of infants by the urolithin-producing bacterium during their first year of life were explored. Two trials (proof-of-concept study: = 11; validation study: = 30) were conducted, where breastfeeding mothers consumed walnuts as a dietary source of urolithin precursors. An analytical method was developed and validated to characterize the urolithin profile in breast milk.

Metabolism of different dietary phenolic compounds by the urolithin-producing human-gut bacteria Gordonibacter urolithinfaciens and Ellagibacter isourolithinifaciens.

Gordonibacter urolithinfaciens and Ellagibacter isourolithinifaciens are two human gut bacterial species that convert ellagic acid into urolithins. Urolithins are bioactive postbiotics produced by dehydroxylation reactions catalyzed by different catechol-dehydroxylases. The metabolic ability of these anaerobic bacteria on other dietary-phenolic compounds is unknown.

Identification of Novel Urolithin Metabolites in Human Feces and Urine after the Intake of a Pomegranate Extract.

Urolithins are bioactive gut microbiota metabolites of ellagic acid. Here, we have identified four unknown urolithins in human feces after the intake of a pomegranate extract. The new metabolites occurred only in 19% of the subjects.

Improving the reporting quality of intervention trials addressing the inter-individual variability in response to the consumption of plant bioactives: quality index and recommendations.

Purpose: The quality of the study design and data reporting in human trials dealing with the inter-individual variability in response to the consumption of plant bioactives is, in general, low. There is a lack of recommendations supporting the scientific community on this topic. This study aimed at developing a quality index to assist the assessment of the reporting quality of intervention trials addressing the inter-individual variability in response to plant bioactive consumption.

Circulating levels of butyrate are inversely related to portal hypertension, endotoxemia, and systemic inflammation in patients with cirrhosis.

Short-chain fatty acids (SCFAs) are gut microbiota-derived products that participate in maintaining the gut barrier integrity and host's immune response. We hypothesize that reduced SCFA levels are associated with systemic inflammation, endotoxemia, and more severe hemodynamic alterations in cirrhosis. Patients with cirrhosis referred for a hepatic venous pressure gradient (HVPG) measurement ( = 62) or a transjugular intrahepatic portosystemic shunt placement ( = 12) were included.

Pomegranate Fruit and Juice (cv. Mollar), Rich in Ellagitannins and Anthocyanins, Also Provide a Significant Content of a Wide Range of Proanthocyanidins.

Proanthocyanidins (PAs) were characterized in husk, membranes, arils, and seeds of 'Mollar de Elche' pomegranate cultivar using liquid chromatography-electrospray ionization-ion-trap tandem mass spectrometry after acid catalysis in the presence of phloroglucinol (phloroglucinolysis). PAs were also evaluated in commercial juice and in the juice made in the laboratory by pressing fresh arils. Pomegranate PAs were composed of a very rich mixture of flavan-3-ols: catechin, epicatechin, gallocatechin, epigallocatechin, epigallocatechin gallate, and epicatechin gallate.