Beta-Glucans Supplementation Associates with Reduction in P-Cresyl Sulfate Levels and Improved Endothelial Vascular Reactivity in Healthy Individuals

Abstract

BackgroundOat and barley beta-glucans are prebiotic fibers known for their cholesterol-lowering activity, but their action on the human gut microbiota metabolism is still under research. Although the induction of short-chain fatty acids (SCFA) following their ingestion has previously been reported, no study has investigated their effects on proteolytic uremic toxins p-cresyl sulfate (pCS) and indoxyl sulfate (IS) levels, while others have failed to demonstrate an effect on the endothelial function measured through flow-mediated dilation (FMD).ObjectiveThe aim of our study was to evaluate whether a nutritional intervention with a functional pasta enriched with beta-glucans could promote a saccharolytic shift on the gut microbial metabolism and improve FMD.MethodsWe carried out a pilot study on 26 healthy volunteers who underwent a 2-month dietary treatment including a daily administration of Granoro “Cuore Mio” pasta enriched with barley beta-glucans (3g/100g). Blood and urine routine parameters, serum pCS/IS and FMD were evaluated before and after the dietary treatment.ResultsThe nutritional treatment significantly reduced LDL and total cholesterol, as expected. Moreover, following beta-glucans supplementation we observed a reduction of serum pCS levels and an increase of FMD, while IS serum levels remained unchanged.ConclusionsWe demonstrated that a beta-glucans dietary intervention in healthy volunteers correlates with a saccharolytic shift on the gut microbiota metabolism, as suggested by the decrease of pCS and the increase of SCFA, and associates with an improved endothelial reactivity. Our pilot study suggests, in addition to cholesterol, novel pCS-lowering properties of beta-glucans, worthy to be confirmed in large-scale trials and particularly in contexts where the reduction of the microbial-derived uremic toxin pCS is of critical importance, such as in chronic kidney disease.

Molecular Mechanism of Functional Ingredients in Barley to Combat Human Chronic Diseases

“…Major antiobesity components in barley are β-glucan, resistant starch, polyphenols, dietary fiber, arabinoxylan, tocols, and phytosterols ( Table 2). β-Glucan in barley significantly treats obesity that reduced low-density lipoprotein, total cholesterol, and serum p-cresyl sulfate levels and increased flow-mediated dilation [90,91]. Barley β-glucan can prevent visceral fat (≥100 cm 2 ) obesity and increase faecal scores, but decreased nutrient digestibility and antiobesity [92,93].…”

“…Reduce Chronic Kidney Disease. Barley β-glucans is associated with a saccharolytic shift in the gut microbiota metabolism by a reduction of pCS toxin blood levels and an increase of SCFA production at colonic site, which can reduce the microbial-derived uremic toxin and cardiovascular complications in end-stage renal disease (see Table 3), especially chronic kidney disease [90]. The total cholesterol and triglycerides were reduced, and HDL cholesterol increased in 10% and 20% barley intervention in breakfast diet; however, barley in the diet of stage 3 chronic kidney disease patients has significantly improved the nutritional status and renal functions [126].…”

Vasculopathy in the setting of cardiorenal syndrome: roles of protein-bound uremic toxins

“…Administration of probiotics and prebiotics may possibly reduce indole metabolism by gut bacteria, thus reducing serum IS levels (64). Similarly, administration of symbiotic Probinul neutro reduced total serum p-cresol concentration (45) and improved endothelial reactivity (26). Alteration of the intestinal environment by lubiprostone ameliorated the progression of CKD as well as the accumulation of PBUTs in rats (96).…”

Targeted mutation of barley (1,3;1,4)-β-glucan synthases reveals complex relationships between the storage and cell wall polysaccharide content

“…Barley cultivars with high grain (1,3;1,4)-β-glucan content are preferred by the functional food sector based on its beneficial effect on human health (Cavallero et al, 2002;Collins et al, 2010;Keenan et al, 2007). (1,3;1,4)-β-Glucan is not digested in the small intestine of humans, acting as fermentable dietary fibre that reduces the risk of diet-related conditions such as cardiovascular disease, type II diabetes and colorectal cancer (Brennan and Cleary, 2005;Wood, 2007;Cosola et al, 2017;Ames et al, 2018).…”