Dietary fibre fermentation in the rat intestinal tract: effect of adaptation period, protein and fibre levels, and particle size

1985 ◽  
Vol 54 (3) ◽  
pp. 635-643 ◽  
Author(s):  
Margareta Nyman ◽  
Nils-Georg ASP
Keyword(s):  
Particle Size ◽  
Wheat Bran ◽  
Dietary Fibre ◽  
Dry Weight ◽  
Nitrogen Excretion ◽  
Adaptation Period ◽  
Faecal Excretion ◽  
Faecal Nitrogen ◽  
Main Components ◽  
Different Levels

1. The fermentative breakdown of one resistant type of dietary fibre (wheat bran) and one easily-fermented fibre (low-methoxyl pectin) was studied with respect to the length of the adaptation period and fibre level in the diet. The breakdown of the resistant fibre was also studied regarding the protein level in the diet and particle size of the fibre.2. Prolongation of the adaptation period from 4 to 18 d decreased the faecal dry weight considerably. The excretion of dietary fibre however, was similar, whereas a decrease in faecal nitrogen excretion could be seen.3. A level of dietary protein of less than 50 g/kg impaired the fermentation of wheat-bran fibre, whereas a level higher than 100 g protein/kg did not further increase the degree of fermentation of the fibre.4. The particle size did not change the fermentability of the fibre, equal amounts of the main components of coarse and milled bran being excreted in faeces.5. Two different levels of wheat-bran fibre (48 and 96 g/kg) in the diet did not influence the fibre breakdown. Similar results were obtained with two levels of fibre from low-methoxyl pectin (42 and 84 g/kg), but a tendency towards a decreased percentage of faecal excretion of uronic acids was seen at the lower level of low-methoxyl pectin.

scholarly journals The effect of different levels of wheat bran on iron absorption in rats from bread containing similar amounts of phytate

1982 ◽  
Vol 47 (2) ◽  
pp. 243-249 ◽  
Author(s):  
S. J. Fairweather-Tait
Keyword(s):  
Wheat Bran ◽  
Dietary Fibre ◽  
Iron Absorption ◽  
Control Group ◽  
Faecal Excretion ◽  
Weanling Rats ◽  
Single Meal ◽  
Old Rats ◽  
Brown Bread ◽  
Different Levels

1. Iron absorption was studied in weanling rats using balance techniques from semi-synthetic diets containing dried white bread (60·5 g dietary fibre/kg, White & Southgate, unpublished results), brown bread (130·2 g dietary fibre/kg) or wholemeal bread (221·2 g dietary fibre/kg) at a level of 300 g/kg and compared with a control group given a diet containing added FeSO4 at a similar Fe level to that for the bread groups. The dried bread contained 6·2–6·4 g phytate/kg.2. Absorption of Fe was significantly higher (P < 0·001) in the control group (0·45) than in the white (0·28), brown (0·31) or wholemeal (0·24) groups.3. A second experiment was carried out on 6-week-old rats in which the dried bread was extrinsically labelled with 59Fe and absorption from a single meal measured by both faecal excretion and incorporation of 59Fe into the blood. Control animals were given 59FeSO4 for comparison.4. The excretion of 59Fe (% of administered dose) was significantly lower (P < 0·001) in the control group (31) than in the white (48), brown (45) or wholemeal (47) groups. After 10 d the control group had significantly more 59Fe in the blood than the bread groups, but there were no differences between the bread groups.5. It appears that wheat bran fibre itself has no effect on the retention of Fe from the diet in the rat, when supplied in amounts similar to those found in commercially-available bread.

scholarly journals Fermentation of dietary fibre components in the rat intestinal tract

1982 ◽  
Vol 47 (3) ◽  
pp. 357-366 ◽  
Author(s):  
Margareta Nyman ◽  
Nils-Georg Asp
Keyword(s):  
Dietary Fibre ◽  
Intestinal Tract ◽  
Guar Gum ◽  
Basal Diet ◽  
Dry Weight ◽  
Protein Digestibility ◽  
Nitrogen Excretion ◽  
Uronic Acids ◽  
Faecal Nitrogen ◽  
Micro Organisms

1. The fermentative breakdown of dietary fibre from various sources in the intestinal tract was studied using rat balance experiments and gas–liquid chromatrographic analysis of dietary fibre monomers in feed and faeces.2. On a basal diet with 690 g maize starch/kg but no added fibre, small but detectableamounts of polymeric glucose, rhamnose, arabinose, xylose, galactose, mannose and uronic acids, i.e. sugars occurring in dietary fibre, were excreted in faeces.3. Dietary fibre in wheat bran was rather resistant to fermentation; 63% was recoveredin the faeces. Guar gum, on the other hand, was almost completely fermented, whereas 19 and 25% of the uronic acids in low and high methoxylated pectin respectively, were excreted in faeces. The various constituents of sugar-beet dietary fibre (approximately equal amounts of arabinose-based hemicellulose, pectin and non-starch glucan (cellulose)) showedquite variable availability for micro-organisms in that 6–12% of the arabinose, 17–25% of the uronic acids, and 52–58% of the cellulose were recovered in the faeces.4. Faecal nitrogen excretion increased on addition of any one of the dietary fibre preparations studied, resulting in decreased true and apparent protein digestibility values.5. The faecal dry weight increment was most pronounced when feeding bran and could then almost be accounted for by the remaining fibre and by protein. The less-prominent bulking effect ot guar gum and pectins, that were much more extensively fermented, could be only partly explained by dietary fibre and protein.

scholarly journals Experimental model for in vivo determination of dietary fibre and its effect on the absorption of nutrients in the small intestine

1981 ◽  
Vol 45 (2) ◽  
pp. 283-294 ◽  
Author(s):  
Ann-Sofie Sandberg ◽  
H. Andersson ◽  
B. Hallgren ◽  
Kristina Hasselblad ◽  
B. Isaksson ◽  
...  
Keyword(s):  
Small Intestine ◽  
Wheat Bran ◽  
Dietary Fibre ◽  
Dry Weight ◽  
Direct Analysis ◽  
Fresh Weight ◽  
Wet Weight ◽  
Definition Of

1. An experimental model for the determination of dietary fibre according to the definition of Trowell et al. (1976) is described. Food was subjected to in vivo digestion in ileostomy patients, and the ileostomy contents were collected quantitatively, the polysaccharide components of which were analysed by gas–liquid chromatography and the Klason lignin by gravimetric determination. The model was used for the determination of dietary fibre in AACC (American Association of Cereal Chemists), wheat bran and for studies on the extent of hydrolysis of wheat-bran fibre in the stomach and small intestine. The effect of wheat bran on ileostomy losses of nitrogen, starch and electrolytes was also investigated.2. Nine patients with established ileostomies were studied during two periods while on a constant low-fibre diet. In the second period 16 g AACC wheat bran/d was added to the diet. The ileostomy contents and duplicate portions of the diet were subjected to determinations of wet weight, dry weight, water content, fibre components, starch, N, sodium and potassium.3. The wet weight of ileostomy contents increased by 94 g/24 h and dry weight by 10 g/24 h after consumption of bran. The dietary fibre of AACC bran, determined as the increase in polysaccharides and lignin of ileostomy contents after consumption of bran, was 280 g/kg fresh weight (310 g/kg dry matter). Direct analysis of polysaccharides and lignin in bran gave a value of 306 g/kg fresh weight. Of the added bran hemicellulose and cellulose 80–100% and 75–100% respectively were recovered in ileostomy contents. There was no significant difference between the two periods in amount of N, starch and K found in the ileostomy contents. The Na excretion increased during the ‘bran’ period and correlated well with the wet weight of ileostomy contents.4. In conclusion, it seems probable that determination of dietary fibre by in vivo digestion in ileostomy patients comes very close to the theoretical definition of dietary fibre, as the influence of bacteria in the ileum seems small. Bacterial growth should be avoided by using a technique involving the change of ileostomy bags every 2 h and immediate deep-freezing of the ileostomy contents. True dietary fibre can be determined by direct analysis of polysaccharides and lignin in the food, at least in bran. Very little digestion of hemicellulose and cellulose from bran occurs in the stomach and small bowel. The 10–20% loss in some patients may be due to digestion by the gastric juice or to bacterial fermentation in the ileum, or both. The extra amount of faecal N after consumption of bran, reported by others, is probably produced in the large bowel.

scholarly journals Effects of dietary fibre and tannins from apple pulp on the composition of faeces in rats

1992 ◽  
Vol 67 (3) ◽  
pp. 463-473 ◽  
Author(s):  
L. Bravo ◽  
F. Saura-Calixto ◽  
I. Goni
Keyword(s):  
Dietary Fibre ◽  
Control Diet ◽  
Protein Digestibility ◽  
Nitrogen Excretion ◽  
Adaptation Period ◽  
Once Daily ◽  
Soluble Dietary Fibre ◽  
Male Wistar Rats ◽  
Cross Links ◽  
Faecal Weight

The present study was undertaken to explore the effect of apple pulp on weight and composition of faeces. This material is rich in dietary fibre (DF;620 g dry matter/kg) and contains appreciable amounts of polyphenols. Recent reports indicate that both condensed tannins (CT) and soluble polyphenols form cross-links with protein and inhibit digestive enzymes, affecting the protein digestibility, and may produce a stimulation of endogenous nitrogen excretion. Two groups of male Wistar rats were fed on either a control diet free of DF or a diet containing 100 g apple pulp DF/kg during 7 d after a 4 d adaptation period. Body-weight and food intake were monitored daily and faeces and urine were collected once daily. DF, water content and polyphenolic compounds were measured in faeces, and N content in both faeces and urine. Faecal weight increased in the fibre group by 280 and 240% when compared with wet and dry faecal weights of animals fed on the fibre-free diet. Soluble dietary fibre (SDF) excreted in faeces was 10.9% of the SDF ingested, which suggested a low resistance to fermentation of this fraction. Of the insoluble DF, 43% of the ingested fibre was fermented. Polyphenols were degraded in the intestinal tract. Of the ingested CT, 68.6% was recovered in faeces, while the soluble polyphenols were extensively degraded (85.7% of that ingested). On the other hand, a higher faecal N excretion was observed for the fibre-fed group, suggesting a decrease in the digestibility of the dietary protein and lower apparent digestibility and N balance indices.

scholarly journals Physiological effects of fibre-rich types of bread

1982 ◽  
Vol 47 (3) ◽  
pp. 451-460 ◽  
Author(s):  
W. Van Dokkum ◽  
Anneke Wesstra ◽  
Francien A. Schippers
Keyword(s):  
Particle Size ◽  
Young Adult ◽  
Dietary Fibre ◽  
Physiological Effects ◽  
White Bread ◽  
Faecal Excretion ◽  
Mineral Balance ◽  
High Fibre ◽  
Calcium Magnesium ◽  
Wholemeal Bread

1. Twelve young adult male volunteers were given a low-fibre white bread diet (9 g neutral-detergent fibre (NDF)/d) and a medium-fibre coarse-bran bread diet (22 g NDF/d), each lasting 20 d. In a third period of 20 d the volunteers were subdivided in groups of four, consuming a high-fibre coarse-bran bread diet (35 g NDF/d). a medium-fibre fine-bran bread diet (22 g NDF/d, bran particle size < 0.35 mm) or a wholemeal bread diet (22 g NDF/d), Retention of calcium, magnesium, iron, zinc and copper were determined during each 20 d period.2. An increase of the amount of dietary fibre (through bran in bread) from 9 g to 22 g NDF/d resulted in a significantly increased mineral intake, but also faecal excretion increased significantly; mineral retention remained almost constant.3. Both intake and faecal excretion of all minerals studied, except faecal Ca. increased further (P < 0.05) on the diet providing 35 g NDF/d: only Fe balance decreased significantly. No significant differences with respect to intake, excretion (except urinary Ca) and balance of the minerals could be detected between the coarse-bran bread and fine-bran bread diets providing 22 g NDF/d. Faecal Fe, Cu balance and Mg balance increased significantly during the wholemeal bread period compared to the coarse-bran bread diet providing 22 g NDF.4. Serum cholesterol increased significantly, i.e. by 0.3 mmol/1, during the coarse-bran bread diet providing 22 g NDF, compared to the white-bread diet.5. It is concluded that increasing the amount of bran in bread does not appear to affect mineral balance considerably but there seems to be an influence on mineral availability. The increased intake was accompanied by increased faecal excretion.

scholarly journals Coarse, but not finely ground, dietary fibre increases intestinalFirmicutes:Bacteroidetesratio and reduces diarrhoea induced by experimental infection in piglets

2011 ◽  
Vol 108 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Francesc Molist ◽  
Edgar Garcia Manzanilla ◽  
José Francisco Pérez ◽  
Charles Martin Nyachoti
Keyword(s):  
Particle Size ◽  
Wheat Bran ◽  
Experimental Infection ◽  
Dietary Fibre ◽  
Positive Control ◽  
Negative Control ◽  
Volatile Fatty Acid Concentration ◽  
Before And After ◽  
Weaning Piglets ◽  
Gut Microbial Community

Using dietary fibre to control childhood diarrhoea has rarely been discussed. However, dietary fibre is being proposed to prevent diarrhoea in piglets. The present study aimed to study the effects of introducing fibre in the post-weaning piglet diet and its particle size on the intestinal ecosystem before and after an experimental infection withEscherichia coli. A total of thirty-six post-weaning piglets were assigned to four experimental diets: a negative control (NC) diet, the same diet with 4 % wheat bran coarse (WBc) particle size or finely milled (WBF) and a positive control (PC) diet with an antibiotic. On day 9, animals were challenged withE. coli. Faecal and digesta samples were obtained before and after the experimental infection and changes in the microbial ecosystem were measured. Animals fed the WBc and the PC diets showed a significant reduction in the faecal score compared with the NC diet. The inclusion of WBc in the diet increased total volatile fatty acid concentration, reduced Bacteroidetes in the faeces before and after the experimental infection compared with the NC diet and increased Firmicutes at the end of the experiment. Based on the results, diarrhoea scours and the composition of the pig gut microbial community are modified by the inclusion of a relatively small amount of wheat bran in the diet, being the physical presentation of the fibre a determinant of that difference.

scholarly journals Effect of fibre level, particle size and adaptation period on digestibility and rate of passage as measured at the ileum and in the faeces in the adult rabbit

1992 ◽  
Vol 67 (1) ◽  
pp. 133-146 ◽  
Author(s):  
T. Gidenne
Keyword(s):  
Particle Size ◽  
Small Intestine ◽  
Dietary Fibre ◽  
Water Soluble ◽  
Adult Rabbit ◽  
Adaptation Period ◽  
Digestive Efficiency ◽  
High Fibre Diet ◽  
Fibre Diet ◽  
High Fibre

The use of specific methods other than gravimetric ones to analyse fibre permitted a more precise study of the degradation of cell wall (CW) in the digestive tract. Digesta flow and rate of passage measurements have not been assessed previously in rabbits to investigate fibre digestion and fibre effects simultaneously in the proximal and in the distal segments of the tract. The effect of the level of dietary fibre on ileal and overall digestibility and rate of passage were studied by comparing semi-purified diets containing only one source of CW (dehydrated lucerne (Medicago sativa) meal) given to adult female rabbits. The effect of fibre particle size and adaptation period were also investigated. Measurements of fibre composition using both colorimetric and gas-liquid chromatographic techniques, showed that large amounts of (CW) were degraded in the caecocolic segments. Increasing dietary fibre level reduced the rate of passage but fibre degradation was increased, at the same time a lower digestive efficiency for energy in the small intestine was found. A small quantity of CW was apparently degraded before the caecum, assuming that the water-soluble fraction of CW was essentially implicated. Grinding lucerne meal through a 1 mm instead of a 3 mm screen did not improve CW digestibility in spite of a longer rate of passage in the caeco-colic segments. Adaptation to a high-fibre diet resulted in an higher digestive volume for colon and caecum, related to an improved degradation of CW. Furthermore, digestive efficiency in the small intestine appeared higher for rabbits adapted to a high-fibre diet than that for rabbits initially fed on a low-fibre diet.

scholarly journals Digestion of concentrates in sheep

1971 ◽  
Vol 25 (2) ◽  
pp. 243-252 ◽  
Author(s):  
E. R. Ørskov ◽  
C. Fraser ◽  
I. McDonald
Keyword(s):  
Fatty Acids ◽  
Small Intestine ◽  
Protein Intake ◽  
Crude Protein ◽  
Alimentary Canal ◽  
Volatile Fatty Acids ◽  
Fish Meal ◽  
Nitrogen Excretion ◽  
Faecal Nitrogen ◽  
Different Levels

1. Diets of rolled barley supplemented with urea or fish meal at four different levels were given in a change-over experiment to four sheep with cannulas in the abomasum and in the terminal ileum.2. Estimates were made of the disappearance of protein, ether extractives, starch, and ash in the various segments of the alimentary canal, and of the production of volatile fatty acids when the urea supplements were given.3. The disappearance (Y, g/d) of non-ammonia crude protein from the small intestine increased with increasing protein intake (X, g/d) on the fish-meal diets according to the equation Y = 0.37X+44. There was no increase in the disappearance with the urea supplements.4. In agreement with earlier work, it was shown that faecal nitrogen excretion was influenced to a much greater extent by fermentation in the large intestine than by that in the rumen. There was an apparent synthesis of ether-extractable lipid in the rumen at rates of 21and 18 g/d with the urea and the fish-meal diets respectively.5. The energy of the volatile fatty acids produced when the urea diets were given was estimated to be 59% of the digestible energy consumed.

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