Natural Choline from Egg Yolk Phospholipids Is More Efficiently Absorbed Compared with Choline Bitartrate; Outcomes of A Randomized Trial in Healthy Adults.

Choline is a vitamin-like essential nutrient, important throughout one's lifespan. Therefore, choline salts are added to infant formula, supplements and functional foods. However, if choline is present in a natural form, e.g. bound to phospholipids, it may be more efficiently absorbed. The study's aim was to evaluate if choline uptake is improved after consumption of an egg yolk phospholipid drink, containing 3 g of phospholipid bound choline, compared to a control drink with 3 g of choline bitartrate. We performed a randomized, double blind, cross-over trial with 18 participants. Plasma choline, betaine and dimethylglycine concentrations were determined before and up to six hours after consumption of the drinks. The plasma choline response, as determined by the incremental area under the curve, was four times higher after consumption of the egg yolk phospholipid drink compared with the control drink (p < 0.01). Similar outcomes were also observed for choline's main metabolites, betaine (p < 0.01) and dimethylglycine (p = 0.01). Consumption of natural choline from egg yolk phospholipids improved choline absorption compared to consumption of chemically produced choline bitartrate. This information is of relevance for the food industry, instead of adding choline-salts, adding choline from egg yolk phospholipids can improve choline uptake and positively impact health.

Remote sensing and signaling in kidney proximal tubules stimulates gut microbiome-derived organic anion secretion.

Membrane transporters and receptors are responsible for balancing nutrient and metabolite levels to aid body homeostasis. Here, we report that proximal tubule cells in kidneys sense elevated endogenous, gut microbiome-derived, metabolite levels through EGF receptors and downstream signaling to induce their secretion by up-regulating the organic anion transporter-1 (OAT1). Remote metabolite sensing and signaling was observed in kidneys from healthy volunteers and rats in vivo, leading to induced OAT1 expression and increased removal of indoxyl sulfate, a prototypical microbiome-derived metabolite and uremic toxin. Using 2D and 3D human proximal tubule cell models, we show that indoxyl sulfate induces OAT1 via AhR and EGFR signaling, controlled by miR-223. Concomitantly produced reactive oxygen species (ROS) control OAT1 activity and are balanced by the glutathione pathway, as confirmed by cellular metabolomic profiling. Collectively, we demonstrate remote metabolite sensing and signaling as an effective OAT1 regulation mechanism to maintain plasma metabolite levels by controlling their secretion.

Development of a screening method to determine the pattern of fermentation metabolites in faecal samples using on-line purge-and-trap gas chromatographic-mass spectrometric analysis.

An on-line screening method to analyse volatile organic compounds (VOCs) in faecal samples was developed. VOCs were isolated from a standard solution or faecal samples using a purge-and-trap system and identified and quantified by GC-MS. The experimental conditions were optimised and the performance of the system was evaluated. Linear calibration curves were obtained with correlation coefficients of at least 0.992. RSDs within and between days were less than 10%. The method was successfully applied to the analysis of faecal samples, yielding 135 different volatile organic compounds identified in 11 faecal samples. Of those, 22 VOCs were found in all volunteers, whereas 34 VOCs were person-specific.