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.

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 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 Fermentation of dietary fibre in the intestinal tract: comparison between man and rat

1986 ◽  
Vol 55 (3) ◽  
pp. 487-496 ◽  
Author(s):  
Margareta Nyman ◽  
Nils-Georg Asp ◽  
John Cummings ◽  
Hugh Wiggins
Keyword(s):  
Wheat Bran ◽  
Dietary Fibre ◽  
Intestinal Tract ◽  
Guar Gum ◽  
Regression Coefficient ◽  
Animal Experiments ◽  
Water Soluble ◽  
Physiological Effects ◽  
Similar Extent ◽  
Neutral Sugars

1. The breakdown and faecal bulking capacity of dietary fibre preparations from wheat bran, apple, cabbage, carrot, and guar gum were compared in man and rat.2. The degradation of the fibre showed good correlation between man and rat (r 0.99, regression coefficient 0.86). Wheat bran was the least well-digested, 66 and 59% of the neutral sugars being excreted in faeces of man and rat respectively. The breakdown of the fibre in apple, cabbage, carrot and guar gum was more complete and 4–29% of the neutral sugars were recovered in faeces.3. The main dietary fibre constituents in each preparation were degraded to a similar extent in man and rat. The main dietary fibre constituents of apple, carrot, cabbage and guar gum were almost completely degraded. Of the xylose in wheat bran 45% (man) and 48% (rat) were recovered in faeces. However, the percentage excretion of glucose and arabinose from bran was higher in man.4. A faecal glucan other than cellulose was identified in human faeces after guar gum, and has been provisionally identified as starch. No such glucan occurred in rat faeces.5. A good correlation between the faecal bulking capacity in man and rat was seen (r 0.97, regression coefficient 0.56). Wheat bran had the best bulking capacity, while that of apple, cabbage, carrot and guar gum was less pronounced. Faecal bulking was inversely related to the amount of fibre which was water-soluble in each preparation.6. It is concluded that this rat experimental model is useful for the prediction of fermentative breakdown and bulking capacity of dietary fibre in man. However, more comparative studies are needed to evaluate animal experiments regarding other physiological effects of dietary fibre.

scholarly journals Production, absorption, distribution and excretion of vitamin B12 in sheep

1970 ◽  
Vol 24 (4) ◽  
pp. 857-877 ◽  
Author(s):  
R. M. Smith ◽  
Late H. R. Marston
Keyword(s):  
Small Intestine ◽  
Urinary Excretion ◽  
Alimentary Tract ◽  
Basal Diet ◽  
Dry Weight ◽  
Particulate Material ◽  
Vitamin B ◽  
Deficient Diet ◽  
Faecal Excretion ◽  
Micro Organisms

1. The efficiency of production and utilization of vitamin B12 was studied with sheep given a cobalt-deficient diet with and without supplementary Co (1 mg/d). Vitamin B12 to lignin ratios in rumen contents were used to estimate minimum rates of production and these were related to faecal and urinary excretion. Tissue distribution and excretion of vitamin B12 were studied with [58Co]cyanocobalamin and 5′-deoxyadenosyl[60Co]cobalamin.2. Labelled Co was rapidly sequestered by particulate material in the rumen and was largely excreted in the faeces. Most of the vitamin B12 in whole rumen contents was contained in micro-organisms, but was released on incubation at pH 2. Added cyanocobalamin was partly degraded in the rumen.3. The vitamin B12 to lignin ratio in rumen contents began to decline 1–3 d after cessation of a daily Co drench. Estimated ruminal production of vitamin B12 on full feed was not less than 400–700 μg/d with supplementary Co and 50–110 μg/d from the Co (0.01–0.05 μg/g dry weight) in the basal diet. Production of vitamin B12 appeared to be limited by food intake with or without additional Co.4. At full feed the efficiency of production of vitamin B12 from Co in the basal diet was about 13% while that from added Co was about 3%. Part of the vitamin B12 produced in the rumen was degraded before reaching the faeces and about 5% was absorbed. The minimum total requirements of sheep for vitamin B12 are assessed at about 11 μg/d.5. Injected 5′-deoxyadenosylcobalamin was better retained than injected cyanocobalamin, faecal excretion exceeded urinary excretion with both. Labelled cobalamin was selectively retained by liver (particularly by the mitochondria), kidneys and the walls of parts of the alimentary tract. Vitamin B12 was secreted into the duodenum and reabsorbed in the ileum, but little secretion occurred above the duodenum and little absorption below the small intestine.

scholarly journals Caecal and faecal short-chain fatty acids and stool output in rats fed on diets containing non-starch polysaccharides

1995 ◽  
Vol 73 (5) ◽  
pp. 773-781 ◽  
Author(s):  
C. A. Edwards ◽  
M. A. Eastwood
Keyword(s):  
Guar Gum ◽  
Basal Diet ◽  
Dry Weight ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Time Period ◽  
Male Wistar Rats ◽  
Group 3 ◽  
Group 2

The exact mechanisms by which non-starch polysaccharides increase stool output are unknown. In the present study the hypothesis that the site of fermentation and short-chain fatty acid (SCFA) accumulation is related to the action of non-starch polysaccharides (NSP) on stool output was tested. The basal diet (45 g NSP/kg) of forty-three male Wistar rats was supplemented with 50 g/kg of either guar, karaya, tragacanth, gellan, xanthan or ispaghula for 28 d. A further twenty-three rats were maintained on the basal diet for the same time period. Faeces were then collected over 2 d and caecal contents obtained post-mortem. Caecal and faecal wet and dry weights and SCFA were measured. Each supplement had a different effect on the caecal and faecal contents but they appeared to fall into three groups when compared with the basal diet. In group 1, guar gum affected only caecal SCFA. It had no effect on stool output or faecal SCFA. In group 2, karaya increased caecal SCFA and tragacanth, karaya and xanthan increased faecal SCFA and faecal water. In group 3, ispaghula and gellan had no consistent effect on caecal or faecal SCFA concentrations but increased Total faecal SCFA output and increased faecal wet and dry weight. Although the knowledge that SCFA are rapidly absorbed in the large intestine has led us to believe that they play no role in determining faecal output, these results suggest that in some cases where NSP are slowly fermented, and increase faecal SCFA, the role of the SCFA may need to be reassessed.

scholarly journals Substrates available for colonic fermentation from oat, barley and wheat bread diets. A study in ileostomy subjects

1996 ◽  
Vol 76 (6) ◽  
pp. 797-808 ◽  
Author(s):  
Ågot Lia ◽  
Birgitta Sundberg ◽  
Per Åman ◽  
Ann-Sofie Sandberg ◽  
Göran Hallmans ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Small Bowel ◽  
Dietary Fibre ◽  
Basal Diet ◽  
Dry Weight ◽  
Wheat Bread ◽  
Klason Lignin ◽  
Colonic Fermentation ◽  
Oat Bran ◽  
Gross Energy

Nutrients not absorbed in the small bowel will form substrates for microbial growth in the colon which may have implications for the development of colon cancer. The aim of the present study was to investigate whether fibre-rich oat and barley diets increase the excretion of energy-supplying nutrients from the small bowel compared with a low-fibre wheat diet, and whether a possible. increase could be related to the β-glucan content. Nine ileastomy subjects were served four types of bread together with a low-fibre basal diet (12 g dietary fibre/d). The breads were based on either wheat flour (W diet, 7 g dietary fibre/d), oat bran (OB diet, 29 g dietary fibre/d), the same amount of oat bran with addition of β-glucanase (EC 3.2.1.4) (OBE diet, 19 g dietary fibre/d) or a fibre-rich barley fraction (B diet, 35 g dietary fibre/d). An increased ileal excretion of starch was observed with the barley diet but no effect of the oat β-glucan on starch recovery was found. The NSP + Klason lignin in the ileostomy effluents accounted only for 24, 31, 24 and 35% of the gross energy excretion in the W, OB, OBE and B diet periods respectively. A large part of the dry weight and energy (30, 21, 28 and 27%, in the W, OB, OBE and B diets respectively) in the effluents could not be identified as fat, protein, total starch or NSP + Klason lignin. This unidentified part was probably made up of oligosaccbarides, endogenous losses and nutrient complexes. Methods for identifying and analysing these components should be developed and their role as substrates for colonic fermentation and colon cancer development ought to be investigated.

scholarly journals Influence of Camembert consumption on the composition and metabolism of intestinal microbiota: a study in human microbiota-associated rats

2004 ◽  
Vol 92 (3) ◽  
pp. 429-438 ◽  
Author(s):  
Christophe Lay ◽  
Malène Sutren ◽  
Pascale Lepercq ◽  
Catherine Juste ◽  
Lionel Rigottier-Gois ◽  
...  
Keyword(s):  
Intestinal Microbiota ◽  
Dairy Products ◽  
Basal Diet ◽  
Fermented Milk ◽  
Metabolic Characteristics ◽  
Human Microbiota ◽  
Gradient Gel Electrophoresis ◽  
Metabolic Activities ◽  
Temperature Gradient Gel Electrophoresis ◽  
Micro Organisms

The objective of the present study was to evaluate the consequence of Camembert consumption on the composition and metabolism of human intestinal microbiota. Camembert cheese was compared with milk fermented by yoghurt starters andLactobacillus caseias a probiotic reference. The experimental model was the human microbiota-associated (HM) rat. HM rats were fed a basal diet (HMB group), a diet containing Camembert made from pasteurised milk (HMCp group) or a diet containing fermented milk (HMfm group). The level of micro-organisms from dairy products was measured in faeces using cultures on a specific medium and PCR–temporal temperature gradient gel electrophoresis. The metabolic characteristics of the caecal microbiota were also studied: SCFA, NH3, glycosidase and reductase activities, and bile acid degradations. The results showed that micro-organisms from cheese comprised 105–108bacteria/g faecal sample in the HMCp group.Lactobacillusspecies from fermented milk were detected in HMfm rats. Consumption of cheese and fermented milk led to similar changes in bacterial metabolism: a decrease in azoreductase activity and NH3concentration and an increase in mucolytic activities. However, specific changes were observed: in HMCp rats, the proportion of ursodeoxycholic resulting from chenodeoxycholic epimerisation was higher; in HMfm rats, α and β-galactosidases were higher than in other groups and both azoreductases and nitrate reductases were lower. The results show that, as for fermented milk, Camembert consumption did not greatly modify the microbiota profile or its major metabolic activities. Ingested micro-organisms were able to survive in part during intestinal transit. These dairy products exert a potentially beneficial influence on intestinal metabolism.

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.

Dietary fibre and nitrogen excretion and retention by pigs

1988 ◽  
Vol 19 (1-2) ◽  
pp. 185-189 ◽  
Author(s):  
C.A. Morgan ◽  
C.T. Whittemore
Keyword(s):  
Dietary Fibre ◽  
Nitrogen Excretion
Sign in / Sign up

Export Citation Format

Share Document