A water-soluble fraction from a by-product of wheat increases the formation of propionic acid in rats compared with diets based on other by-product fractions and oligofructose

Abstract

BackgroundDietary fibre is fermented by the colonic microbiota to carboxylic acids (CA), with potential health effects associated in particular with butyric and propionic acid.ObjectiveTo investigate the formation of CA in the hindgut of healthy rats fed dietary fibre from different fractions of wheat shorts, a by-product of the milling of wheat.DesignRats were fed dietary fibre (80 g/kg feed per day for 7 days) from wheat shorts and fractions thereof (ethanol-soluble, water-soluble and insoluble fractions), oligofructose (OF) diet and a mixture of oligofructose and raffinose (OR) diet.ResultsThe water-soluble fraction, with a high content of arabinoxylan (AX), increased the formation of propionic acid in the hindgut and lowered the ratio of acetic to propionic acid in the portal blood of rats. High levels and proportions of butyric acid were seen in rats fed the OR diet. The pattern of CA resulting from the ethanol-soluble diet, mainly composed of fructan and raffinose, was more similar to that of the OF diet than the OR diet.ConclusionsThe high formation of propionic acid with the water-soluble fraction may be attributed to the high AX content. The results also indicate that the wheat fructans produced more propionic acid and less butyric acid than OF. It may furthermore be speculated that the formation of butyric acid associated with the OR diet was due to a synergetic effect of OR.

Barley Products of Different Fiber Composition Selectively Change Microbiota Composition in Rats

“…A decrease of Akkermansia muciniphila , the only known species of this genus, has been related to an increased risk to develop ulcerative colitis and obesity . Intake of water‐extractable arabinoxylan derived from wheat has previously been linked with an increased formation of propionic acid in the cecum of rats . Also in the present study, diets containing higher proportions of soluble arabinoxylan contributed with a higher cecal proportion of propionic acid (Table and ), which could especially be seen in cecum of rats fed AX extract, which could be the reason for the higher abundance of Akkermansia with this material.…”

“…Taking the characteristics of the fiber in consideration, diets with more soluble arabinoxylan contributed to a higher proportion of propionic acid in the cecum of rats (Table and ), which was especially seen in rats fed AX extract. High proportions of propionic acid in the cecum of rats have also been related to the content of soluble arabinoxylans in a previous study . Interestingly, soluble fiber, soluble arabinoxylan, β‐glucan, and β‐glucan Mw were all positively correlated with the proportion of propionic acid, but negatively with acetic acid in the cecum of rats fed malt/BSG diets ( Table ).…”

“…According to in vitro studies, some Bifidobacterium and Lactobacillius strains can utilize xylan oligosaccharides but not β‐glucan . Furthermore, soluble arabinoxylan from wheat are considered to be butyrogenic and propiogenic, in humans and rats, respectively, and related with the increase of Roseburia, Prevotella , and Bifidobacterium in studies on rodents …”

Gut metabolites associated with pH and antioxidant capacity during in vitro colonic fermentation of Mexican corn products

“…Mexico has the highest per capita consumption of corn. The microbiota exerts a primordial role in the fermentation of soluble dietary fiber and RS that leads to the production of short-chain fatty acids (SCFA), mainly acetic, propionic, and butyric acids (Hask a, Andersson, & Nyman, 2011). The nixtamal obtained (endosperm and germ) is pounded to yield a soft dough that is used in the preparation of tortilla.…”

“…The gut microbiota can either produce harmful metabolites associated with certain pathologies or beneficial compounds that protect against diseases. The microbiota exerts a primordial role in the fermentation of soluble dietary fiber and RS that leads to the production of short-chain fatty acids (SCFA), mainly acetic, propionic, and butyric acids (Hask a, Andersson, & Nyman, 2011). In addition, nitrogenous compounds (fermentation products of resistant proteins), particularly p-cresol, are potential cancer promoters and exert carcinogenic effects (Andriamihaja et al, 2015).…”