pectins and Weight-Gain

To come even closer to the functional composition of human milk, acidic oligosaccharides (AOS) from pectin were added to well known neutral prebiotics (galacto-oligosaccharides (GOS) and long-chain fructo-oligosaccharides (FOS)). The effect of AOS and GOS/FOS/AOS on intestinal flora, stool characteristics as well as acceptance and tolerance was investigated.. Human milk contains 75% to 85% neutral and 15% to 25% acidic oligosaccharides. In this prospective, randomized, double blind study, a mixture of 80% neutral oligosaccharides (from long-chain galacto- and long-chain fructo-oligosaccharides) with 20% acidic oligosaccharides derived from pectin hydrolysis was investigated. Forty-six term infants were fed a standard formula supplemented with either maltodextrin as control (n=15), or with 0.2 g acidic oligosaccharides (n=16), or with the latter plus 0.6 g neutral oligosaccharides (mixture of galacto- and fructo-oligosaccharides; n=15). Fecal flora using plating technique and pH were measured. Stool characteristics and possible side effects (crying, vomiting, and regurgitation) were recorded.. There was no difference in the bifidobacteria counts between the control and the group supplemented with acidic oligosaccharides alone (8.75+/-0.50 vs. 8.58+/-0.94 log colony forming units [CFU]/g stool). In infants fed the combination of acidic and neutral oligosaccharides, bifidobacteria were increased (9.61+/-0.70 log CFU/g stool; P<0.01). The same pattern was observed with lactobacilli. Stool consistency was softest in infants fed the complete oligosaccharide mixture, but also in those fed formula supplemented with acidic oligosaccharides alone, the stool consistency was significantly softer compared with the control group. Fecal pH increased in the controls, remained constant in acidic oligosaccharides alone, and decreased in the complete mixture of oligosaccharides group.. There was no difference in growth, crying, vomiting, and regurgitation patterns between the groups. In summary, acidic oligosaccharides from pectin hydrolysate are well tolerated as ingredient in infant formulae but do not affect intestinal microecology.

Topics: Bifidobacterium; Colony Count, Microbial; Double-Blind Method; Feces; Female; Humans; Hydrogen-Ion Concentration; Infant; Infant Food; Infant Formula; Infant Nutritional Physiological Phenomena; Infant, Newborn; Intestines; Lactobacillus; Male; Oligosaccharides; Pectins; Probiotics; Prospective Studies; Weight Gain

This study was aimed at determining potential effects of apple-derived pectin on weight gain, gut microbiota, gut barrier and metabolic endotoxemia in rat models of diet-induced obesity. The rats received a standard diet (control; Chow group; n = 8) or a high-fat diet (HFD; n = 32) for eight weeks to induce obesity. The top 50th percentile of weight-gainers were selected as diet induced obese rats. Thereafter, the Chow group continued on chow, and the diet induced obese rats were randomly divided into two groups and received HFD (HF group; n = 8) or pectin-supplemented HFD (HF-P group; n = 8) for six weeks. Compared to the HF group, the HF-P group showed attenuated weight gain (207.38 ± 7.96 g vs. 283.63 ± 10.17 g, p < 0.01) and serum total cholesterol level (1.46 ± 0.13 mmol/L vs. 2.06 ± 0.26 mmol/L, p < 0.01). Compared to the Chow group, the HF group showed a decrease in Bacteroidetes phylum and an increase in Firmicutes phylum, as well as subordinate categories (p < 0.01). These changes were restored to the normal levels in the HF-P group. Furthermore, compared to the HF group, the HF-P group displayed improved intestinal alkaline phosphatase (0.57 ± 0.20 vs. 0.30 ± 0.19, p < 0.05) and claudin 1 (0.76 ± 0.14 vs. 0.55 ± 0.18, p < 0.05) expression, and decreased Toll-like receptor 4 expression in ileal tissue (0.76 ± 0.58 vs. 2.04 ± 0.89, p < 0.01). The HF-P group also showed decreased inflammation (TNFα: 316.13 ± 7.62 EU/mL vs. 355.59 ± 8.10 EU/mL, p < 0.01; IL-6: 51.78 ± 2.35 EU/mL vs. 58.98 ± 2.59 EU/mL, p < 0.01) and metabolic endotoxemia (2.83 ± 0.42 EU/mL vs. 0.68 ± 0.14 EU/mL, p < 0.01). These results suggest that apple-derived pectin could modulate gut microbiota, attenuate metabolic endotoxemia and inflammation, and consequently suppress weight gain and fat accumulation in diet induced obese rats.

Topics: Animals; Anti-Obesity Agents; Bacteria; Biomarkers; Cholesterol; Diet, High-Fat; Disease Models, Animal; Endotoxemia; Fruit; Gastrointestinal Microbiome; Hypercholesterolemia; Inflammation Mediators; Intestinal Mucosa; Intestines; Lipopolysaccharides; Male; Malus; Obesity; Pectins; Permeability; Phytotherapy; Plants, Medicinal; Rats, Sprague-Dawley; Tight Junctions; Time Factors; Weight Gain

Atherosclerosis is a major risk factor for cardiovascular disease (CVD) and stroke. Galectin-3 is a carbohydrate-binding lectin implicated in the pathophysiology of CVD and is highly expressed within atherosclerotic lesions in mice and humans. The object of this present study was to use genetic deletion and pharmacological inhibition in a well-characterized mouse model of atherosclerosis to determine the role of galectin-3 in plaque development. Apolipoprotein-E/galectin-3 knockout mice were generated and fed a high-cholesterol "western" diet. Galectin-3 deletion had no consistent effect on the serum lipid profile but halved atherosclerotic lesion formation in the thoracic aorta (57% reduction), the aortic arch (50% reduction) and the brachiocephalic arteries. The aortic plaques were smaller, with reduced lipid core and less collagen. In apolipoprotein E-deficient (ApoE(-/-)) mice, there was a switch from high inducible nitric oxide expression in early lesions (6 weeks) to arginase-1 expression in later lesions (20 weeks), which was reversed in ApoE(-/-)/gal-3(-/-) mice. Administration of modified citrus pectin, an inhibitor of galectin-3, during the latter stage of the disease reduced plaque volume. We conclude that inhibiting galectin-3 causes decreased atherosclerosis. Strategies to inhibit galectin-3 function may reduce plaque progression and potentially represent a novel therapeutic strategy in the treatment of atherosclerotic disease.

Topics: Animals; Aorta, Thoracic; Apolipoproteins E; Arginase; Arginine; Atherosclerosis; Cell Line; Cell Movement; Fatty Acids, Nonesterified; Galectin 3; Humans; Macrophages; Mice; Mice, Inbred C57BL; Mice, Knockout; Pectins; Plaque, Atherosclerotic; Triglycerides; Weight Gain

In the present in vitro study, the effects of pH and ionic strength on the release of iron from pectin and the ability of pectin to reduce ferric iron to ferrous iron were examined. The bioavailability of Fe bound to pectin was evaluated in rats. The amount of Fe released from pectin was at a maximum at pH 2·0 and decreased as the pH value increased. At pH 2·0, the amount of Fe released from pectin increased as the ion length increased; at pH 5·0, ion length had no effect on pectin release. Pectin effectively reduced Fe from the ferric form to the ferrous form. In rats fed a pectin diet, where Fe bound to pectin was the only Fe source, the final Hb concentration using diets containing 4·4-5·7, 7·2 or 11·5 mg Fe/kg diet was equal to the concentration in rats fed diets containing 4·5, 7·6 or 13·5 mg ferrous iron/kg diet, respectively. Hb regeneration efficiencies in rats fed pectin diets were significantly different from rats fed a diet containing 13·5 mg ferrous iron/kg diet. In rats fed a diet with or without pectin, where ferric iron was the only Fe source, pectin increased the final Hb concentration. These results suggest that Fe bound to pectin is utilised by rats.

Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Diet; Hydrogen-Ion Concentration; Iron; Male; Osmolar Concentration; Pectins; Rats; Rats, Wistar; Weight Gain

Topics: Diet; Dietary Fiber; Fermentation; Food Additives; Fruit; Humans; Intestines; Pectins; Vegetables; Weight Gain

The present study was undertaken to investigate how three different fibre sources, sugar beet pulp, soya bean hulls and pectin residue, constituting 15% of diets for growing pigs, influenced daily body gain, feed conversion, apparent faecal digestibility and nitrogen and energy balances. Eight castrated crossbreed pigs (30-80 kg live weight) were used in a replicated 4 x 4 Latin-square design with one control diet and three fibre containing diets. Daily body weight gain and feed conversion were not affected by the dietary treatments. The apparent faecal digestibility of organic matter (OM) and energy were significantly lower for the fibre diets (OM: 0.81-0.85; energy: 0.78-0.83) compared to the control diet (OM: 0.88; energy: 0.86). The apparent faecal digestibility of crude protein (CP) was lower for the fibre diets (0.71-0.78) compared to the control diet (0.83), although it was only significantly lower for the sugar beet pulp and pectin residue diets. The pectin residue diet, which contained the highest amount of dietary fibre, lignin and insoluble non-starch polysaccharides, had the lowest digestibility of OM, CP and energy. There was a tendency (p = 0.07) for a diet effect on retained nitrogen in proportion to digested nitrogen, where the sugar beet pulp and pectin residue diets had numerically the highest values. Heat production and retained energy in proportion to metabolizable energy intake were not affected by fibre inclusion. It was concluded that the inclusion of sugar beet pulp, soya bean hulls and pectin residue in diets for growing pigs decreased the apparent faecal digestibility and in the diets with sugar beet pulp and pectin residue higher utilization of digested nitrogen for retention compensated for the lower amount of digested nitrogen.

Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Beta vulgaris; Dietary Fiber; Digestion; Dose-Response Relationship, Drug; Energy Metabolism; Male; Nitrogen; Pectins; Random Allocation; Solubility; Swine; Weight Gain

Eight-month-old Sprague-Dawley rats were fed on diets containing dietary fiber at the 5% level for 3 weeks to examine the effect on the lipid metabolism and immune function. Among cellulose, guar gum, partially hydrolyzed guar gum (PHGG), glucomannan and highly methoxylated pectin, guar gum induced a significant decrease in the food intake and weight gain, as well as a significant increase in the liver weight. In addition, the epidydimal adipose tissue weight of the rats fed on PHGG was significantly higher than that of the rats fed on cellulose. There was no significant effect on the serum lipid levels, but the serum IgG level of the rats fed on guar gum was significantly lower than that of the rats fed on cellulose. The IgA and IgG productivity in mesenteric lymph node (MLN) lymphocytes was significantly higher in the rats fed on guar gum, glucomannan and pectin than in those fed on cellulose, while the effect on Ig productivity in spleen lymphocytes was not as marked. In addition, only guar gum induced a significant increase of IgM productivity in MLN lymphocytes when compared to the cellulose group. These results suggest that enhancement of the immune function by dietary fiber is mainly expressed in the gut immune system.

Topics: Aging; Animals; Cellulose; Dietary Fiber; Eating; Hydrolysis; Immunoglobulins; Lipids; Liver; Male; Mannans; Organ Size; Pectins; Rats; Rats, Sprague-Dawley; Weight Gain

We investigated the degradation, metabolism, fate, and selected effects of pectin in the intestinal tract of rats. Conventional and germfree rats were fed for 3 wk diets containing 6.5% pectin (degree of methylation 34.5, 70.8 and 92.6%, respectively) or pectin-free diets. Pectin passes the small intestine as a macromolecule. The molecular weight distribution of pectins isolated from intestinal contents of germfree rats were unaffected by diet. No or very little galacturonan was found in cecum, colon or feces of most of the conventional rats. In colon contents of some conventional rats, di- and trigalacturonic acid were present. Total anaerobic and Bacteroides counts were greater in groups fed pectin. The concentration of short-chain fatty acids (SCFA) was higher in cecum and feces in all pectin-fed groups. With increasing degree of methylation, the formation rate of SCFA decreased in the cecum of conventional rats. During in vitro fermentation of pectin with fecal flora from rats, unsaturated oligogalacturonic acids appeared as intermediate products. Low-methoxyl pectin was fermented faster than high-methoxyl pectins in vivo and in vitro. Pectin-fed rats had greater ileum, cecum and colon weights. We conclude that structural parameters of pectin influence its microbial degradation in the intestinal tract.

Topics: Animals; Behavior, Animal; Colony Count, Microbial; Eating; Fatty Acids, Volatile; Feces; Food Irradiation; Gastrointestinal Contents; Germ-Free Life; In Vitro Techniques; Intestinal Mucosa; Intestines; Male; Methylation; Organ Size; Pectins; Rats; Rats, Inbred Strains; Weight Gain

Pectin is a soluble indigestible polysaccharide that stimulates cecal polyamine formation in rats. Bacteroides and fusobacteria, two numerically dominant bacterial population groups in the large intestine, were found to synthesize in vitro high amounts of spermidine and putrescine. The purpose of this study was to elucidate the effect of pectin on the polyamine production by defined bacterial species in vivo. Germfree male Wistar rats (n = 18) were randomly assigned to one of three treatments: (i) monoassociation with Bacteroides thetaiotaomicron + fiber-free diet; (ii) diassociation with B. thetaiotaomicron + Fusobacterium varium + fiber-free diet or (iii) diassociation with B. thetaiotaomicron + F. varium + fiber-free diet + 10% pectin. The cecal contents of monoassociated rats fed fiber-free diet contained large amounts (1.51+/-0.21 micromol/dry total cecum content) of spermidine which was the major polyamine. The cecum of diassociated rats fed the fiber-free diet contained even higher concentrations of spermidine (2.53+/-0.21 micromol/dry total cecum content) and also putrescine, which was now the dominant polyamine (putrescine 0.32+/-0.28 vs. 3.01+/-0.28 micromol/dry total cecum content; monoassociation vs. diassociation). Pectin consumption by diassociated rats led to an additional increase in the cecal concentrations of all polyamines: putrescine, spermidine and spermine were 40, 37 and 100%, respectively, higher in the diassociated rats consuming the pectin diet than in those consuming the pectin-free diet. Since the microbial counts in the cecum did not differ in the diassociated treatment groups, the elevated concentrations of polyamines observed in the pectin group must have been due to stimulated bacterial polyamine synthesis. The decline of individual polyamines from cecum to feces detected at the end of the study in all treatment groups and the high microbial counts in the cecum and in feces suggest that bacterial polyamines are absorbed in cecum and colon. Pectin stimulates intestinal microbes to synthesize large amounts of polyamines which may be utilized by the host.

Topics: Analysis of Variance; Animals; Bacteroides; Cecum; Diet; Dietary Fiber; Energy Intake; Feces; Fusobacterium; Humans; Hydrogen-Ion Concentration; Male; Pectins; Putrescine; Rats; Rats, Wistar; Spermidine; Weight Gain

A study was conducted with conventional and germ-free broiler chicks to obtain more information on the role of the intestinal microflora in the anti-nutritive effects of NSP in broiler chicks. As the NSP source, highly methylated citrus pectin (HMC) was used at a dose level of 30 g/kg in a maize-based diet. The diets fed to the germ-free chicks were gamma-irradiated, whereas those fed to the conventional chicks were not. Feeding the HMC diet to conventional birds depressed weight gain and food utilization (P < 0.05), whereas in germ-free birds only weight gain was reduced (P < 0.05). Feeding the HMC diet to conventional birds reduced digestibilities of energy and starch at the end of the jejunum. Ileal digestibilities of starch and energy were not strongly affected when birds were fed on the HMC-containing diet. Faecal digestibilities of organic matter, crude fat, starch and amino acids, N retention and metabolizable energy were reduced when conventional chicks were fed on the HMC diet. Feeding the HMC diet to germ-free birds hardly affected faecal digestibility of nutrients and N retention, whereas metabolizable energy was increased. Feeding the HMC diet to conventional or germ-free birds increased the viscosity of the digesta in the small intestine. This increase in digesta viscosity was more pronounced in conventional than in germ-free birds. The pH of ileal digesta was reduced when HMC was added to the diet of conventional chicks, but not in germ-free chicks. Feeding the HMC diet to conventional birds markedly affected morphology of the gut wall, whereas in germ-free chicks very little effect was found on gut morphology. Based on the results of the present study, it is concluded that the gastrointestinal microflora mediates the magnitude of the anti-nutritive effects of HMC in broiler chicks. However, the exact role of the microflora in chicks in the magnitude of the anti-nutritional effects of HMC could not be derived from the present study, since the results might have been influenced by gamma-irradiation of the diets fed to the germ-free chicks.

Topics: Animals; Chickens; Citrus; Digestion; Energy Metabolism; Gastrointestinal Contents; Germ-Free Life; Intestines; Male; Nerve Tissue Proteins; Nutritive Value; Pectins; Viscosity; Weight Gain

1. The aim of this study was to examine the effects of dietary fibre sources on growth and on the development of the gastro-intestinal tract in growing geese. 2. Six-week-old female White Roman geese were divided at random into 6 groups with 6 dietary treatments. Diets were isoenergetic and isonitrogenous and contained alfalfa meal, barley bran, rice hulls, cellulose, pectin or lignin as the major dietary source of fibre. 3. Food intake was significantly higher in the barley bran group than in the other groups. Both daily weight gain and food conversion of the pectin and alfalfa meal groups were lower than those of the other groups. 4. In the 9-week-old geese, the relative weight and the length of the small intestine did not significantly differ among treatment groups. However, the relative weight was significantly lightest and the caecal length was significantly shortest (P < 0.05) in the pectin group. 5. Activities of amylase and cellulose hydrolases of the caecal contents were also highest in the pectin group. 6. From SEM micrographs, no morphological damage of the villi was observable in the different intestinal segments of the geese in any of the treatments.

Topics: Amylases; Animal Nutritional Physiological Phenomena; Animals; Cecum; Cellulase; Cellulose; Cellulose 1,4-beta-Cellobiosidase; Dietary Fiber; Female; Geese; Hordeum; Intestines; Lignin; Medicago sativa; Oryza; Pectins; Weight Gain

To determine the relationship among colonocyte proliferation, differentiation, and apoptosis as a function of fiber and carcinogen, we conducted a 2 x 2 factorial design study with two fibers (pectin or cellulose) and two injection protocols (azoxymethane or saline) in male Sprague-Dawley rats. Rats were killed six weeks after the injections, and in vivo cell proliferation was measured by incorporation of bromodeoxyuridine into DNA, differentiation by binding of the lectin Dolichos biflorus agglutinin, and apoptosis by immunoperoxidase detection of digoxigenin-labeled genomic DNA. In the proximal colon, pectin decreased differentiation and apoptosis, resulting in a greater number of cells per crypt column. In the distal colon, pectin increased cell proliferation, resulting in more crypts per millimeter of colon and a greater number of surface cells. Azoxymethane increased cell proliferation and decreased differentiation and apoptosis in the proximal and the distal colon. This resulted in a greater number of surface cells proximally and more crypts per millimeter of colon distally. These results illustrate the importance of considering all three parameters (proliferation, differentiation, and apoptosis) when evaluating neoplastic growth.

Topics: Animals; Apoptosis; Azoxymethane; Bromodeoxyuridine; Carcinogens; Cell Differentiation; Cell Division; Colon; Dietary Fiber; DNA; Eating; Epithelial Cells; Feces; Intestinal Mucosa; Male; Pectins; Rats; Rats, Sprague-Dawley; Weight Gain

The morphological changes in the intestinal tunica muscularis induced by prolonged dietary fiber intake were determined in rat small intestine and colon with the aid of computerized image analysis. Thirty male Sprague-Dawley rats were fed either a fiber free, 15% cellulose or 15% pectin diet for 8 weeks. Intestine length was measured and stained cross sections of the jejunum, ileum, and colon were quantitated using image analysis. In the distal colon, muscle cell size was also determined. Despite lower weight gain in the pectin fed rats, both the small intestine and colon length were significantly increased. Cellulose feeding had a lesser effect on intestine length. Pectin fed rats had significantly increased relative tunica muscularis area (37.2 +/- 2.2 mm2) in ileum cross sections when compared to control (24.3 +/- 1.8 mm2) and cellulose fed rats (26.1 +/- 1.1 mm2). In the mid-colon, the tunica muscularis area was found to be pectin > cellulose > control (33.5 +/- 2.2; 29.7 +/- 1.7; 25.8 +/- 1.5 respectively) with significant differences reached between pectin and control rats. In jejunal samples, no differences were observed among the groups. Circular smooth muscle cell size in the distal colon was significantly increased following cellulose feeding but was less pronounced in the case of pectin. We conclude that fiber supplementation leads to morphological changes in the rat intestine including changes in length and tunica muscularis volume.

Topics: Animals; Cellulose; Colon; Dietary Fiber; Image Processing, Computer-Assisted; Intestinal Mucosa; Intestine, Small; Male; Muscle, Smooth; Pectins; Rats; Rats, Sprague-Dawley; Time Factors; Weight Gain

Rats were fed a semi purified diet containing 0.5% cholesterol and 10% fiber (cellulose, pectin, psyllium seed and defatted psyllium husk). One additional group of rats was fed cholesterol (0.5%) as part of a fiber-free diet and another was fed the fiber free diet without cholesterol. Cellulose had virtually no effect on serum or liver lipids. Pectin had a lipid lowering effect. Psyllium seed exerted an effect on total serum cholesterol equal to that of pectin but gave higher levels of HDL-cholesterol. The effects of psyllium seed on liver lipids were more pronounced than those of pectin. Defatted psyllium husk feeding virtually normalized liver size and serum triglyceride levels and produced lower serum total cholesterol levels and higher HDL-cholesterol than observed in normal controls. Defatted psyllium husk feeding also yielded liver lipid values which were in the normal range. Fecal wet and dry weights were significantly higher in rats fed either psyllium preparation.

Topics: Analysis of Variance; Animals; Cellulose; Cholesterol, Dietary; Cholesterol, HDL; Dietary Fiber; Feces; Lipid Metabolism; Lipids; Liver; Male; Organ Size; Pectins; Phospholipids; Plantago; Plants, Medicinal; Rats; Rats, Sprague-Dawley; Seeds; Triglycerides; Weight Gain

Bile acid composition, synthetic rate and pool size were determined in rats fed diets containing 5 g cellulose, 5 g pectin or 5 g psyllium hydrocolloid/100 g diet using the washout technique. Bile acid pool sizes were similar for pectin- and psyllium-fed rats, and both were higher than the pool size for rats fed cellulose (5.48 +/- 1.22, 4.70 +/- 0.71 and 1.77 +/- 0.41 mumol/100 g body wt, respectively). Bile acid secretion rates showed a similar pattern [1730 +/- 496, 1551 +/- 252 and 572 +/- 88 nmol/(h.100 g body wt)], as did basal synthetic rates [129 +/- 25, 126 +/- 42 and 87 +/- 18 pmol/(h.100 g body wt)]. Individual and total bile acid pool sizes were generally higher in animals fed the pectin- or psyllium-supplemented diet compared with rats fed cellulose. Pectin or psyllium consumption resulted in a lower hydrophobicity of the bile acid pool and a lower ratio of circulating 12 alpha-hydroxylated to non-12 alpha-hydroxylated bile acids compared with cellulose consumption. This reduced hydrophobicity has been shown to reduce feedback inhibition of bile acid synthesis and may be responsible for the larger bile acid pool size. Changes in the location of reabsorption of bile acids may also be responsible for changes in the pool size and composition. These changes are characteristic of greater sterol excretion.

Topics: Animals; Bile; Bile Acids and Salts; Chemical Phenomena; Chemistry, Physical; Colloids; Deoxycholic Acid; Dietary Fiber; Intestinal Absorption; Male; Pectins; Psyllium; Rats; Rats, Wistar; Weight Gain

The mechanism by which fermentable fibers may stimulate colonic cell proliferation was tested using two types of fiber (highly fermentable pectin, and less fermentable wheat bran), measuring in vivo concentrations of short-chain fatty acids (SCFA) in the cecum and the proximal and distal colon of rats and correlating these concentrations with cell proliferation indices at the same locations within the intestine. Pectin supplementation resulted in higher concentrations of propionate in proximal and distal colon as compared with fiber-free controls, whereas wheat bran resulted in a higher concentration of butyrate at every site. In the cecum, pH had the strongest correlation to indices of cell proliferation. The lower the pH the greater the number of cells per crypt column (P < 0.05), cells per crypt circumference (P < 0.01), and total number of cells per crypt (P < 0.001). Butyrate had the strongest correlation between a specific SCFA and indices of cell proliferation. In the distal colon, butyrate concentration was positively correlated with number of cells per crypt column (P < 0.05) and total number of cells per crypt (P < 0.05). This study shows that different fibers are fermented to different SCFA in different amounts and that the in vivo concentration of certain of these SCFA is significantly correlated with cell proliferation indices.

Topics: Analysis of Variance; Animals; Cecum; Cell Division; Colon; Dietary Fiber; Eating; Fatty Acids, Volatile; Feces; Fermentation; Hydrogen-Ion Concentration; Male; Pectins; Rats; Rats, Sprague-Dawley; Weight Gain

The effects of the degree of esterification (DE) and the molecular weight (MW) of pectins on iron bioavailability were investigated in anemic rats. The pectins prepared differed (in DE and MW, respectively) as follows: P-A (73%, 860,000), P-B (75%, 89,000), P-C (22%, 1,260,000) and P-D (24%, 114,000). Rats were fed an iron-deficient diet (8 mg Fe/kg diet) for 14 d. The anemic rats were then fed a ferrous sulfate-supplemented basal diet (47 mg Fe/kg diet) or the basal diet containing one of the pectins (80 g/kg diet) for 10 d. None of the pectins used caused any significant reduction in the bioavailability of ferrous sulfate. Addition of pectin P-B to the diet resulted in significantly greater iron repletion. Compared with control rats fed with ad libitum access or pair-fed, rats fed P-B showed higher (P < 0.05) hemoglobin regeneration efficiency, hematocrit, serum iron concentration, and transferrin saturation, and lower unsaturated iron-binding capacity and total iron-binding capacity. Pectins P-A and P-D also slightly improved the hematological indices compared with P-C and control. The observed effects were dependent on the physicochemical properties of each pectin as determined by its MW and DE.

Topics: Anemia, Hypochromic; Animals; Biological Availability; Dietary Carbohydrates; Eating; Erythrocyte Indices; Esterification; Hematocrit; Hemoglobins; Iron; Male; Molecular Weight; Pectins; Rats; Transferrin; Weight Gain

1. Bile acids were analysed in the bile and lumen samples of rats which received a cholesterol-free or cholesterol-enriched (5 g/kg) diet free from fibre, or containing cellulose or citrus pectin at the level of 100 g/kg. 2. Dietary pectin but not cellulose increased biliary bile acid concentration and excretion. Dietary cholesterol did not affect biliary bile acids quantitatively. 3. Biliary bile acids were almost exclusively conjugated with glycine or taurine in the various experimental situations. The predominant portion of bile acids in rats fed on the cholesterol-free diet was conjugated with taurine when the diet was either free from fibre or contained cellulose; the ratio of bile acids conjugated with glycine: those conjugated with taurine (G:T) was less than 0.2. In contrast, with pectin as a fibre source, the conjugation with glycine increased enormously (G:T increased to approximately 4). Cholesterol enrichment of the diet also increased the glycine conjugation in all groups of rats. Even in this situation, the G:T was highest in rats fed on pectin. 4. Pectin, but not cellulose, increased the bile acid content of the small intestine and caecum, both in rats fed on the cholesterol-free and cholesterol-enriched diets. Cholesterol feeding doubled the bile acid content of the caecum in rats fed on a fibre-free diet or a cellulose diet, but not in those fed on pectin. No such effect of cholesterol was observed in the small intestine, except for the ileal bile acid content in rats fed on cellulose. 5. A considerable portion of the bile acids in the small intestine was deconjugated. The extent of the deconjugation was higher in the ileum than in the jejunum. As in the bile, G:T in rats fed on pectin (3-5.5) were higher than those in the other groups (0.05-1.05) in various situations. Also, cholesterol feeding considerably increased the ratio in all groups of rats. 6. The observed dietary alteration of the partition of bile acids between glycine and taurine may be of physiological significance in regulating bile acid and lipid metabolism in rats.

Topics: Animals; Bile Acids and Salts; Cellulose; Cholesterol, Dietary; Dietary Fiber; Feces; Glycine; Intestine, Small; Male; Pectins; Rats; Rats, Inbred Strains; Taurine; Weight Gain

Two experiments were carried out in which rats were offered diets containing different amounts and types of dietary fibre, i.e. commercial stock diet and three semi-purified diets containing no fibre, 200 g wheat bran or 200 g pectin/kg. Dietary inclusion of fibre, and especially pectin, stimulated large bowel fermentation, as indicated by caecal hypertrophy and reduced caecal pH. After 3 weeks, mucosal:serosal zinc transfer and Zn accumulation by tissue were measured using the everted-gut-sac technique. In Expt 2, incubations were carried out in the presence and absence of 0.25 mM-ouabain to assess the importance of transfer by Na+,K+-ATPase-dependent mechanisms, and some observations on glucose transport were also made. Ouabain reduced rates of transfer of both Zn and glucose and also tissue Zn accumulation. There were no significant differences in rates of Zn transfer by everted sacs from duodenal, ileal and colonic sites, but accumulation of Zn by tissue was a more important fate than transfer across the serosal surface, and accumulation by duodenal tissue was approximately twice as great as by other tissues. Mucosal:serosal transfer of glucose by ileal tissue was much more sensitive to ouabain than was Zn transfer. Previous diet appeared to alter the capacity of the intestinal tissue to transfer Zn, with the highest rates of transfer being by colonic tissue from pectin-fed rats.

Topics: Animals; Cecum; Dietary Fiber; Glucose; Intestinal Absorption; Male; Pectins; Rats; Rats, Inbred Strains; Weight Gain; Zinc