Evaluation of the prebiotic properties of wheat arabinoxylan fractions and induction of hydrolase activity in gut microflora.
ABSTRACT Dietary supplementation with prebiotics may result in the stimulation of the growth of beneficial bacteria such as lactobacilli and bifidobacteria in the human gastrointestinal tract. The effect of water-unextractable arabinoxylans (WU-AX) derived from wheat on the modulation of gut bacterial composition was investigated using a mixed culture fermentation system. A prebiotic index (PI) score of 2.03 was obtained after addition of 1% (w/v) WU-AX to a pH-controlled stirred anaerobic fermentation vessel. Pretreatment of the WU-AX with endo-beta-1,4-xylanase resulted in significantly higher PI value (3.48) indicating that pretreatment provided oligomers that were better utilised by the gut bacteria. The extracellular hydrolytic enzymes xylanase and ferulic acid esterase are both required for bacterial metabolism of WU-AX and both activities were present in supernatants derived from the mixed batch cultures. Addition of the WU-AX substrates to the batch cultures produced several fold increases of bacterial synthesis of both enzymes, and these increases were greater when the WU-AX substrate was pretreated with xylanase.
Article: Prebiotic activity of polysaccharides extracted from Gigantochloa levis (Buluh beting) shoots.[show abstract] [hide abstract]
ABSTRACT: Bamboo shoot crude polysaccharides (BSCP) extracted from the shoots of Gigantochloa levis gave about 3.27 ± 0.18% on dry basis and a very minute percentage of protein (0.02 ± 0.01%). The molecular weight of BSCP estimated by gel chromatography was found to be around 7.49 × 103 Da, while the molecular weights of purified fractions (F1 to F5) were around 1550.96, 1471.63, 1685.78, 1691.61 and 1551.67 Da, respectively. The FTIR spectrum of BSCP revealed the possibility that the extract contains β-glucan, which can be considered a valuable compound for the medical and food industries. These relate to the resistance of BSCP towards artificial human gastric juice which is more than 99%. Prebiotic activity tested using BSCP as a carbon source showed significant increase in the growth of B. animalis ATCC 1053, B. longum BB 536 and L. acidophilus ATCC 4356 as compared to the use of FOS. Survivality of S. choleraesuis JCM 6977 was found to be slower in both BSCP and FOS. Study conducted reflects a good sign for the BSCP to be exploited as a promising prebiotic.Molecules 01/2012; 17(2):1635-51. · 2.39 Impact Factor
Article: In vitro fermentation of arabinoxylan-derived carbohydrates by bifidobacteria and mixed fecal microbiota.[show abstract] [hide abstract]
ABSTRACT: Bifidobacterium adolescentis ATCC 15703, Bifidobacterium breve ATCC 15700, Bifidobacterium longum ATCC 15707, and human fecal microbiota were cultivated in vitro with d-xylose, l-arabinose, xylo-oligosaccharides (XOS), and arabinoxylo-oligosaccharides (AXOS) as carbon sources. The pH, formation of volatile fatty acids, and carbohydrate utilization profiles were followed. In the pure bifidobacteria cultures optical density and in the fecal slurries pressure and H(2) were also detected. A differing substrate preference was observed among the various bifidobacteria strains. B. adolescentis grew on XOS, slowly on d-xylose, but not on l-arabinose. In contrast, B. longum preferred l-arabinose and did not grow on pure d-xylose or XOS. Both strains were able to utilize AXOS but with differing strategies, since after the cleavage of l-arabinose B. adolescentis consumed the XOS formed, whereas B. longum fermented the l-arabinose released. B. breve grew poorly on all of the substrates provided. A bifidobacterial mixture and the fecal microbiota were able to utilize pure singly substituted AXOS almost completely, but pure AXOS with a doubly substituted xylose residue was fermented only by the fecal microbiota. Thus, AXOS appear to be potential candidates for slowly fermenting prebiotics, but their prebiotic effects may be dependent on the type of arabinose substitution and the presence of other carbohydrates.Journal of Agricultural and Food Chemistry 09/2009; 57(18):8598-606. · 2.82 Impact Factor
Article: Prebiotic effects of wheat arabinoxylan related to the increase in bifidobacteria, Roseburia and Bacteroides/Prevotella in diet-induced obese mice.[show abstract] [hide abstract]
ABSTRACT: Alterations in the composition of gut microbiota--known as dysbiosis--has been proposed to contribute to the development of obesity, thereby supporting the potential interest of nutrients targeting the gut with beneficial effect for host adiposity. We test the ability of a specific concentrate of water-extractable high molecular weight arabinoxylans (AX) from wheat to modulate both the gut microbiota and lipid metabolism in high-fat (HF) diet-induced obese mice. Mice were fed either a control diet (CT) or a HF diet, or a HF diet supplemented with AX (10% w/w) during 4 weeks. AX supplementation restored the number of bacteria that were decreased upon HF feeding, i.e. Bacteroides-Prevotella spp. and Roseburia spp. Importantly, AX treatment markedly increased caecal bifidobacteria content, in particular Bifidobacterium animalis lactis. This effect was accompanied by improvement of gut barrier function and by a lower circulating inflammatory marker. Interestingly, rumenic acid (C18:2 c9,t11) was increased in white adipose tissue due to AX treatment, suggesting the influence of gut bacterial metabolism on host tissue. In parallel, AX treatment decreased adipocyte size and HF diet-induced expression of genes mediating differentiation, fatty acid uptake, fatty acid oxidation and inflammation, and decreased a key lipogenic enzyme activity in the subcutaneous adipose tissue. Furthermore, AX treatment significantly decreased HF-induced adiposity, body weight gain, serum and hepatic cholesterol accumulation and insulin resistance. Correlation analysis reveals that Roseburia spp. and Bacteroides/Prevotella levels inversely correlate with these host metabolic parameters. Supplementation of a concentrate of water-extractable high molecular weight AX in the diet counteracted HF-induced gut dysbiosis together with an improvement of obesity and lipid-lowering effects. We postulate that hypocholesterolemic, anti-inflammatory and anti-obesity effects are related to changes in gut microbiota. These data support a role for wheat AX as interesting nutrients with prebiotic properties related to obesity prevention.PLoS ONE 01/2011; 6(6):e20944. · 4.09 Impact Factor