In Vitro Fermentation by Human Fecal Microflora of Wheat Arabinoxylans

Abstract

The fermentation of three arabinoxylan (AX) fractions from wheat by the human fecal microflora was investigated in vitro. Three AX fractions, with average molecular masses of 354, 278, and 66 kDa, were incorporated into miniature-scale batch cultures (with inulin as a positive prebiotic control) with feces from three healthy donors, aged 23-29. Microflora changes were monitored by the culture-independent technique, fluorescent in situ hybridization, and short chain fatty acid (SCFA) and lactic acid production were measured by high-performance liquid chromatography. Total cell numbers increased significantly in all treated cultures, and the fermentation of AX was associated with a proliferation of the bifidobacteria, lactobacilli, and eubacteria groups. Smaller but statistically significant increases in bacteroides and clostridia groups were also observed. All AX fractions had comparable bifidogenic impacts on the microflora at 5 and 12 h, but the 66 kDa AX was particularly selective for lactobacilli. Eubacteria increased significantly on all AX fractions, particularly on 66 kDa AX. As previously reported, inulin gave a selective increase in bifidobacteria. All supplemented cultures showed significant rises in total SCFA production, with a particularly high proportion of butyric acid being produced from AX fermentation. The prebiotic effect, that is, the selectivity of AX for bifidobacteria and lactobacilli groups, increased as the molecular mass of the AX decreased. This suggests that molecular mass may influence the fermentation of AX in the colon.

Artificial simulation of salivary and gastrointestinal digestion, and fermentation by human fecal microbiota, of polysaccharides fromDendrobium aphyllum

“…34 It has been reported that colonic microbiota obtains its energy mainly by oxidizing SCFAs in the order of butyric > valeric > propionic > acetic acid, which means that microbial metabolism activity also inuences the proprieties of SCFAs.…”

Gut microorganisms as promising targets for the management of type 2 diabetes

“…Arabinoxylans (AX), the most abundant nondigestible carbohydrates in wheat, are predominantly present in bran and aleurone fractions [87,88]. AX are selectively degraded in the colon by intestinal bacteria expressing xylanases and arabinofuranosidases and represent a new class of prebiotics [89][90][91]. Table 1 summarises the findings of studies on AX and AXOS (short-chain AX produced via enzymatic processing) in animal models and in humans.…”

Preparation of Bamboo Hemicellulose Hydrolysate Possessing Anti-oxidative Properties and Their Effects on Mice Plasma Cholesterol

“…It was previously reported that in aged mice fed a HF diet, supplementation with long-chain wheat arabinoxylan polysaccharides, likely gramineous as well as bamboo hemicelluloses, inhibited increases in plasma cholesterol levels, while those fed HF diet alone showed significant increases in plasma cholesterol levels (Lopez et al, 1999;Lu et al, 2004;Hughes et al, 2007;Neyrinck and Delzenne, 2010). I added it into the References.…”