Bioavailability of orange juice (poly)phenols: the impact of short-term cessation of training by male endurance athletes

Background: Physical exercise has been reported to increase the bioavailability of citrus flavanones. Objective: To investigate the bioavailability of orange juice (OJ) (poly)phenols in endurance-trained men before and after cessation of training for 7 days. Design: Ten fit endurance-trained males, with a maximal oxygen consumption of 58.2 ± 5.3 mL/kg/min, followed a low (poly)phenol diet for 2 d before drinking 500 mL of OJ, containing 398 µmol of (poly)phenols of which 330 µmol were flavanones. After the volunteers stopped training for 7 days the feeding study was repeated. Urine samples were collected 12 h pre- and 24 h post-OJ orange consumption. Bioavailability was assessed by the quantitative analysis of urinary flavanone metabolites and (poly)phenol catabolites using HPLC-HR-MS. Results: While training, 0-24 h urinary excretion of flavanone metabolites, mainly hesperetin-3-O-glucuronide, hesperetin-3´-sulfate, naringenin-4´-O-glucuronide, naringenin-7-O-glucuronide, was equivalent to 4.2% of OJ flavanone intake. This increased significantly to 5.2% when OJ was consumed after the volunteers stopped training for 7 days. Overall, this trend, although not significant, was also observed with OJ-derived colonic catabolites which after supplementation in the trained state were excreted in amounts equivalent to 51% of intake compared to 59% after cessation of training. However, urinary excretion of three colonic catabolites of bacterial origin, most notably, 3-(3´-hydroxy-4´-methoxyphenyl)hydracrylic acid, did increase significantly when OJ was consumed post- compared to pre-cessation of training. Data were also obtained on inter-individual variations in flavanone bioavailability. Conclusion: A 7-day cessation of endurance training enhanced, rather than reduced, the bioavailability of OJ flavanones. The biological significance of these differences and, whether or not they extend to the bioavailability of other dietary (poly)phenols, remains to be determined. Hesperetin-3´-O-glucuronide and the colonic microbiota-derived catabolite 3-(3´-hydroxy-4´-methoxyphenyl)hydracrylic acid are key biomarkers of the consumption of hesperetin-O-glycoside-containing OJ and other citrus products

Identification of plasma and urinary metabolites and catabolites derived from orange juice (poly)phenols: analysis by high-performance liquid chromatography–high-resolution mass spectrometry

Orange juice is a rich source of (poly)phenols, in particular, the flavanones hesperetin-7-O-rutinoside and naringenin-7-O-rutinoside. Following the acute consumption of 500 mL of orange juice containing 398 μmol of (poly)phenols by 12 volunteers, 0–24 h plasma and urine samples were analyzed by targeted high-performance liquid chromatography–high-resolution mass spectrometry in order to identify flavanone metabolites and phenolic acid and aromatic catabolites. A total of 19 flavanone metabolites—comprising di-O-glucuronide, O-glucuronide, O-glucuronyl-sulfate, and sulfate derivatives of hesperetin, naringenin, and eriodictyol—and 65 microbial-derived phenolic catabolites, such as phenylpropanoid, phenylpropionic, phenylacetic, benzoic, and hydroxycarboxylic acids and benzenetriol and benzoylglycine derivatives, including free phenolics and phase II sulfate, glucuronide, and methyl metabolites, were identified or partially identified in plasma and/or urine samples. The data obtained provide a detailed evaluation of the fate of orange juice (poly)phenols as they pass through the gastrointestinal tract and are absorbed into the circulatory system prior to renal excretion. Potential pathways for these conversions are proposed

The molecular basis of phosphite and hypophosphite recognition by ABC-transporters

Inorganic phosphate is the major bioavailable form of the essential nutrient phosphorus. However, the concentration of phosphate in most natural habitats is low enough to limit microbial growth. Under phosphate-depleted conditions some bacteria utilise phosphite and hypophosphite as alternative sources of phosphorus, but the molecular basis of reduced phosphorus acquisition from the environment is not fully understood. Here, we present crystal structures and ligand binding affinities of periplasmic binding proteins from bacterial phosphite and hypophosphite ATP-binding cassette transporters. We reveal that phosphite and hypophosphite specificity results from a combination of steric selection and the presence of a P-H…π interaction between the ligand and a conserved aromatic residue in the ligand-binding pocket. The characterisation of high affinity and specific transporters has implications for the marine phosphorus redox cycle, and might aid the use of phosphite as an alternative phosphorus source in biotechnological, industrial and agricultural applications

Dynamics of extracellular superoxide production by Trichodesmium colonies from the Sargasso Sea

Author Posting. © Association for the Sciences of Limnology and Oceanography, 2016. This article is posted here by permission of Association for the Sciences of Limnology and Oceanography for personal use, not for redistribution. The definitive version was published in Limnology and Oceanography 61 (2016): 1188–1200, doi:10.1002/lno.10266.Reactive oxygen species (ROS) are key players in the health and biogeochemistry of the ocean and its inhabitants. The vital contribution of microorganisms to marine ROS levels, particularly superoxide, has only recently come to light, and thus the specific biological sources and pathways involved in ROS production are largely unknown. To better understand the biogenic controls on ROS levels in tropical oligotrophic systems, we determined rates of superoxide production under various conditions by natural populations of the nitrogen-fixing diazotroph Trichodesmium obtained from various surface waters in the Sargasso Sea. Trichodesmium colonies collected from eight different stations all produced extracellular superoxide at high rates in both the dark and light. Colony density and light had a variable impact on extracellular superoxide production depending on the morphology of the Trichodesmium colonies. Raft morphotypes showed a rapid increase in superoxide production in response to even low levels of light, which was not observed for puff colonies. In contrast, superoxide production rates per colony decreased with increasing colony density for puff morphotypes but not for rafts. These findings point to Trichodesmium as a likely key source of ROS to the surface oligotrophic ocean. The physiological and/or ecological factors underpinning morphology-dependent controls on superoxide production need to be unveiled to better understand and predict superoxide production by Trichodesmium and ROS dynamics within marine systems.Major support for this work was provided by NSF OCE- 1246174 to CMH, NSF OCE-1332912 to STD and NSF OCE-13329898 to BASVM

Transcriptional responses of Trichodesmium to natural inverse gradients of Fe and P availability

The filamentous diazotrophic cyanobacterium Trichodesmium is responsible for a significant fraction of marine di-nitrogen (N2) fixation. Growth and distribution of Trichodesmium and other diazotrophs in the vast oligotrophic subtropical gyres is influenced by iron (Fe) and phosphorus (P) availability, while reciprocally influencing the biogeochemistry of these nutrients. Here we use observations across natural inverse gradients in Fe and P in the North Atlantic subtropical gyre (NASG) to demonstrate how Trichodesmium acclimates in situ to resource availability. Transcriptomic analysis identified progressive upregulation of known iron-stress biomarker genes with decreasing Fe availability, and progressive upregulation of genes involved in the acquisition of diverse P sources with decreasing P availability, while genes involved in N2 fixation were upregulated at the intersection under moderate Fe and P availability. Enhanced N2 fixation within the Fe and P co-stressed transition region was also associated with a distinct, consistent metabolic profile, including the expression of alternative photosynthetic pathways that potentially facilitate ATP generation required for N2 fixation with reduced net oxygen production. The observed response of Trichodesmium to availability of both Fe and P supports suggestions that these biogeochemically significant organisms employ unique molecular, and thus physiological responses as adaptations to specifically exploit the Fe and P co-limited niche they construct

Sustainable travel behaviour and the widespread impacts on the local economy

Statistics show that unsustainable travel behaviour and global greenhouse gas emissions are growing and due to the perceived indispensable nature of personal travel, shifts to more sustainable modes remain a challenge. Automobility supports sustained local economic growth but also raises issues around safety, health, road fatalities, traffic and congestion, and detrimental environmental impacts. This article addresses the issue of sustainable mobility by investigating how to increase sustainable travel choices and, where this is not possible, ensure existing travel choices and patterns are as environmentally friendly as possible. Existing soft initiatives aimed at increasing sustainable travel behaviour fail to fully acknowledge that travel decisions are made at the individual level and that tailored strategies would be more effective at targeting distinct behavioural patterns. Influencing changes in travel behaviour at the local level demonstrates significant potential where individual behaviour can be influenced if appropriate support at the system level is in place and complies with the needs of individuals. This article demonstrates that, in doing so, this will simultaneously address other areas, such as accessibility, employability, health and sustainable growth, crucial to the establishment and survival of automobility by both supporting local economic growth and achieving reductions in carbon emissions

Randomised clinical study: inulin short-chain fatty acid esters for targeted delivery of short-chain fatty acids to the human colon

SUMMARY Background Short-chain fatty acids (SCFA) produced through fermentation of nondigestible carbohydrates by the gut microbiota are associated with positive metabolic effects. However, well-controlled trials are limited in humans

Metaverse beyond the hype: Multidisciplinary perspectives on emerging challenges, opportunities, and agenda for research, practice and policy

The metaverse has the potential to extend the physical world using augmented and virtual reality technologies allowing users to seamlessly interact within real and simulated environments using avatars and holograms. Virtual environments and immersive games (such as, Second Life, Fortnite, Roblox and VRChat) have been described as antecedents of the metaverse and offer some insight to the potential socio-economic impact of a fully functional persistent cross platform metaverse. Separating the hype and “meta…” rebranding from current reality is difficult, as “big tech” paints a picture of the transformative nature of the metaverse and how it will positively impact people in their work, leisure, and social interaction. The potential impact on the way we conduct business, interact with brands and others, and develop shared experiences is likely to be transformational as the distinct lines between physical and digital are likely to be somewhat blurred from current perceptions. However, although the technology and infrastructure does not yet exist to allow the development of new immersive virtual worlds at scale - one that our avatars could transcend across platforms, researchers are increasingly examining the transformative impact of the metaverse. Impacted sectors include marketing, education, healthcare as well as societal effects relating to social interaction factors from widespread adoption, and issues relating to trust, privacy, bias, disinformation, application of law as well as psychological aspects linked to addiction and impact on vulnerable people. This study examines these topics in detail by combining the informed narrative and multi-perspective approach from experts with varied disciplinary backgrounds on many aspects of the metaverse and its transformational impact. The paper concludes by proposing a future research agenda that is valuable for researchers, professionals and policy makers alike