Tag Archives: animal

COS, Like FOS, Increases Calcium Retention, Bone Density and Strength in Rats

Abstract

Effect of chitooligosaccharides on calcium bioavailability and bone strength in ovariectomized rats.

Chitosan polymer with deacetylation degree of 93% was hydrolyzed with an endo-type chitosanase (35,000 U/g protein) with substrate to enzyme ratio of 1 to 1.5 for 18 h in a batch reactor, and then the resultant hydrolysates were fractionated into four different molecular weights using an ultrafiltration (UF) membrane reactor system. An in vitro study elucidated that four kinds of chitooligosaccharides (COSs) could efficiently inhibit the formation of insoluble calcium salts in the neutral pH. In vivo effects of COSs on Ca bioavailability were further studied in the osteoporosis modeling rats induced by ovariectomy and concurrent low calcium intake. During the experimental period corresponding to the menopause with the osteoporosis disease, calcium retention was increased and bone turnover was decreased by COS IV supplementation in the ovariectomized (OVX) rats. After the low Ca diet, COS IV diet including both normal level of calcium and vitamin D significantly decreased calcium loss in feces and increased calcium retention compared to the control diet. The levels of femoral total calcium, bone mineral density (BMD), and femoral strength were also significantly increased by the COS IV diet in a similar level to those of CPP diet group. In the present study, the results proved the beneficial effects of low molecular chitooligosaccharide (COS IV) in preventing negative mineral balance.

Jung WK, Moon SH, Kim SK
Life Sci. Jan 2006
PMID: 16137703

Review: Inulin and FOS Mechanisms

Abstract

Inulin, oligofructose and bone health: experimental approaches and mechanisms.

Inulin-type fructans have been proposed to benefit mineral retention, thereby enhancing bone health. Many, but not all, experimental animal studies have shown increased mineral absorption by feeding non-digestible oligosaccharides. Possible reasons for inconsistencies are explored. A few studies have reported an enhanced bone mineral density or content. Bone health can be evaluated in chronic feeding studies with bone densitometry, bone breaking strength, bone mineral concentration and bone structure. Isotopic Ca tracers can be used to determine the point of metabolism affected by feeding a functional food ingredient. These methods and the effects of feeding inulin-type fructose are reviewed. Inulin-type fructans enhance Mg retention. Chicory long-chain inulin and oligofructose enhance femoral Ca content, bone mineral density and Ca retention through enhanced Ca absorption and suppressed bone turnover rates, but it is not bone-promoting under all conditions.

Weaver CM
Br. J. Nutr. Apr 2005
PMID: 15877902

FOS Increases Efficiency of Isoflavones in Rats

Abstract

Fructooligosaccharides maximize bone-sparing effects of soy isoflavone-enriched diet in the ovariectomized rat.

Isoflavones (IF) have been increasingly implicated for use in the prevention of osteoporosis. As their bioavailability could be improved by modulating intestinal microflora, the present study was undertaken to investigate whether IF and fructooligosaccharides (FOS), which are known to modify large-bowel flora and metabolism, may exhibit a cooperative bone-sparing effect. This work was carried out on 3-month-old Wistar rats assigned to 12 groups: 2 SH (sham-operated) and 10 OVX (ovariectomized). Animals received a diet for 90 days containing total IF (Prevastei HC, Central Soya) at 0 (OVX and SH), 10 (IF10), 20 (IF20), 40 (IF40), or 80 (IF80) microg/g body weight per day. FOS (Actilight, Beghin-Meiji) were orally given to half of the groups, (OVX FOS), (IF10 FOS), (IF20 FOS), (IF40 FOS), (IF80 FOS), and (SH FOS). Isoflavones exhibited a bone-sparing effect as soon as consumption reached 20 microg/g/day, whereas only the highest dose induced a weak uterotrophic activity. Indeed, total femoral bone mineral density (BMD) was significantly enhanced (compared with that of OVX rats), as was the metaphyseal compartment. Bone strength was improved as well. As far as the FOS diet is concerned, addition of prebiotics significantly raised the efficiency of the IF protective effect on both femoral BMD and mechanical properties. The trend toward higher BMD levels with the lowest IF dose (IF10) even reached a significant level when FOS were added. This effect could be explained by a reduced bone resorption. In conclusion, daily IF consumption prevented castration-induced osteopenia by decreasing bone resorption when given at 20, 40, or 80 microg (total isoflavones)/g/day. Simultaneous FOS consumption improved IF protective effect on the skeleton, with the lowest IF dose becoming efficient. Enhancement of IF bioavailability, following FOS fermentation, is probably involved.

Mathey J, Puel C, Kati-Coulibaly S, Bennetau-Pelissero C…
Calcif. Tissue Int. Aug 2004
PMID: 15164148

FOS + Inulin Increase Calcium Absorption and Bone Parameters in Rats

Abstract

Nondigestible oligosaccharides increase calcium absorption and suppress bone resorption in ovariectomized rats.

Nondigestible oligosaccharides (NDO) including inulin and fructooligosaccharides (FOS) have been reported to stimulate calcium absorption. Here we report the effect of a mixture of inulin and FOS (Raftilose Synergy 1, Orafti) on calcium and bone metabolism in ovariectomized (OVX) rats. OVX rats (6 mo old) were fed a semipurified diet for 3 mo in our animal care laboratory for stabilization after ovariectomy. They were then divided into two groups (n = 13/group) and fed either a control or a NDO-supplemented diet (55 g/kg) for 21 d. Catheters were placed in their jugular veins. After 2 d, a tracer ((45)Ca) was administered by gavage or i.v. and blood was sampled for up to 300 min. Urine and fecal samples were collected for 4 d after (45)Ca administration. Femurs were measured for bone mineral density (BMD), breaking strength, and total calcium. Calcium absorption, femoral calcium content, BMD, and bone balance (V(bal)) were significantly increased (P < 0.05) by NDO, whereas the bone resorption rate relative to the bone formation rate was significantly depressed by NDO. We conclude that feeding NDO at 5.5 g/100 g for 21 d has a positive effect on calcium absorption and retention in ovariectomized rats.

Zafar TA, Weaver CM, Zhao Y, Martin BR…
J. Nutr. Feb 2004
PMID: 14747679 | Free Full Text

Note, unfortunately, there was no improvement in breaking strength.

FOS Prevents Femur Neck Osteopenia in Gastrectomized Rats

Abstract

Fructooligosaccharides prevent disorders of the femoral neck following gastrectomy in growing rats.

Gastrectomy-evoked osteopenia in the femoral metaphysis of rats can be prevented by the consumption of fructooligosaccharides (FOS). We examined the effect of FOS on the femoral neck. Twenty-eight 5-week-old male Sprague-Dawley rats were divided into two groups, sham-operated (SH) and gastrectomized (GX). One week after each operation, the rats were fed diets containing 0.5% calcium with or without 7.5% FOS for 4 weeks. After dietary treatment, the middle of the femoral neck was cross sectioned. Backscattered electron images of the sections were then taken to calculate the following morphometric parameters: (1) percent trabecular bone volume (%TBV), (2) percent cortical bone volume (%CBV), and (3) percent bone marrow cavity (%MV); all were determined relative to the entire scan area (SC). Calcium, phosphorus, and magnesium (weight percent) were then measured on the cortical bone by energy-dispersive X-ray analysis. Total bone volume (%BV = %TBV + %CBV) and %CBV were almost identical among the groups, except in GX rats. In GX rats, these variables were significantly (approximately 20% and 30%, respectively; P < 0.01) less than those in SH rats, whereas there were no changes in the other groups over the entire scan area. The calcium concentration close to the periosteal surface of cortical bone was markedly reduced by gastrectomy. This reduction was completely prevented by FOS consumption. These results suggest that FOS consumption prevents gastrectomy-evoked osteopenia regarding both volume and calcium concentration of the femoral neck.

Hirama Y, Morohashi T, Sano T, Maki K…
J. Bone Miner. Metab. 2003
PMID: 12928830

Inulin Increases Whole-Body Bone Minerals in Rats

Abstract

Dietary chicory inulin increases whole-body bone mineral density in growing male rats.

Chicory inulin is a natural linear fructan that is not digested in the upper part of the gastrointestinal tract but is fermented in the cecocolon. It enhances calcium absorption in rats and improves femur and tibia mineral contents in gastrectomized or ovariectomized rats. We studied the effect of inulin (0, 5 and 10 g/100 g diet) on whole-body bone mineral content (WBBMC), whole-body bone area (WBBA) and whole-body bone mineral density (WBBMD) in live, growing male rats fed diets containing 0.2, 0.5 or 1 g Ca/100 g. Three experiments, each corresponding to one of the different dietary Ca concentrations, were performed using male Wistar rats (n = 108; 4 wk old). WBBMC was measured by dual-energy X-ray absorptiometry every 4 wk up to wk 22. Inulin increased WBBMC (P < 0.05) and WBBMD (P < 0.001) significantly but not WBBA at all ages and all dietary calcium concentrations. This is the first report to demonstrate that chicory inulin not only increases calcium absorption but also increases mineral parameters in whole-body bones.

Roberfroid MB, Cumps J, Devogelaer JP
J. Nutr. Dec 2002
PMID: 12468594 | Free Full Text

FOS Most Effective with High Calcium in Mice

Abstract

Effect of oligofructose or dietary calcium on repeated calcium and phosphorus balances, bone mineralization and trabecular structure in ovariectomized rats.

We investigated the effects of dietary oligofructose and Ca on bone structure in ovariectomized rats, using microradiography and histomorphometry. Ninety-six animals were allocated to seven experimental groups: G1, sham-operated; G2-G7, ovariectomized. Semi-purified diets containing 5 g Ca/kg (recommended content) without oligofructose (G1, G2) or with 25, 50 or 100 g oligofructose/kg (G3, G4, G5) or 10 g Ca/kg (high content) without oligofructose (G6) or with 50 g oligofructose/kg (G7) were fed for 16 weeks. At the recommended level of Ca, high oligofructose (G5) increased femur mineral levels in ovariectomized rats, while medium oligofructose did so at high Ca. Increasing Ca in the absence of oligofructose did not increase femur mineral content. Trabecular bone area (%) analysed in the tibia was 10.3 (sem 1.2) (G1), 7.7 (sem 0.6) (G2), 9.3 (sem 0.7) (G3), 9.4 (sem 1.0) (G4), 9.5 (sem 0.7) (G5), 10.2 (sem 0.8) (G6), and 12.6 (sem 0.8) (G7). At the recommended level of Ca, 25 g oligofructose/kg prevented loss of trabecular area due to increased trabecular thickness, while 50 or 100 g oligofructose/kg increased trabecular perimeter. At high Ca, oligofructose prevented loss of bone area due to increased trabecular number but similar thickness (G7 v. G6). When Ca was raised in the presence of oligofructose (G7), trabecular area and cortical thickness were highest, while loss of trabecular connectivity was lowest of all groups. At the same time, lumbar vertebra Ca was higher; 44.0 (sem 0.8) (G7) compared with 41.6 (sem 0.8) (G2), 41.4 (sem 0.7) (G4), and 40.5 (sem 1.0) mg (G6). We conclude that ovariectomy-induced loss of bone structure in the tibia was prevented but with different trabecular architecture, depending on whether dietary Ca was increased, oligofructose was incorporated, or both. Oligofructose was most effective when dietary Ca was high.

Scholz-Ahrens KE, Açil Y, Schrezenmeir J
Br. J. Nutr. Oct 2002
PMID: 12323086

FOS Increases Isoflavone Bioavailability in Mice

Abstract

A combination of dietary fructooligosaccharides and isoflavone conjugates increases femoral bone mineral density and equol production in ovariectomized mice.

Fructooligosaccharides (FOS) stimulate the growth of bifidobacteria, which cleave isoflavone conjugates to yield the corresponding aglycones and metabolites. In a previous study, FOS modified the absorption and enterohepatic recirculation of isoflavones in rats. In the present study, we determined the effect of the combination of dietary FOS and isoflavone conjugates on bone mass in ovariectomized (OVX) and surgical control mice. After undergoing OVX or sham operation, female ddY mice (8 wk old, n = 64) were randomly assigned to four groups: a purified control diet (AIN-93G) group, a FOS diet (AIN-93G + 5% FOS) group, an isoflavone diet (AIN-93G + 0.2% isoflavone conjugates) group, or a FOS and isoflavone diet (AIN-93G + 5% FOS + 0.2% isoflavone conjugates) group. After 6 wk, the mice were killed and the blood and femora were sampled immediately. In OVX mice, both isoflavone conjugates and FOS prevented femoral bone loss. An additive effect of dietary isoflavone conjugates and FOS was observed by dual-energy X-ray absorptiometry in the distal part of the femur and in trabecular bone, by peripheral quantitative computed tomography. Moreover, FOS increased cecal beta-glucosidase activity and equol production from daidzein in both OVX and surgical control mice fed isoflavone conjugates. These results suggest that FOS increase the bioavailability of isoflavones, leading to cooperative effects in the prevention of osteopenia in OVX mice.

Ohta A, Uehara M, Sakai K, Takasaki M…
J. Nutr. Jul 2002
PMID: 12097691 | Free Full Text

FOS Prevents Bone Loss in Gastrectomized Rats

Abstract

Dietary fructooligosaccharides prevent a reduction of cortical and trabecular bone following total gastrectomy in rats.

Fructooligosaccharides (FOS) have been shown to stimulate the absorption of several minerals in the intestine. In the present study, the effects of FOS on osteopenia induced by total gastrectomy were examined. Twenty eight male Sprague Dawley rats were divided into 2 groups: sham-operated (SH) and gastrectomized (GX). After a one-week adaptation period following surgery, the rats were fed synthetic diets with or without 7.5% FOS for 5 weeks. The right femur was then examined by soft X-ray, and the bone mineral density (BMD) was measured. Based on the soft X-ray findings, both cancellous and cortical bone were markedly decreased in GX rats, but not in GX + FOS rats. GX rats showed a 30% lower BMD in the metaphysis and a 20% lower BMD in the diaphysis, compared with SH rats (P < 0.01). As assessed by morphometry, significant decreases were observed in cortical bone in the diaphysis and trabecular bone in the distal metaphysis (P < 0.01). On the other hand, dietary FOS completely prevented these changes following gastrectomy. These findings indicate that dietary FOS might contribute to the prevention of bone diseases following gastrectomy.

Morohashi T, Ohta A, Yamada S
Jpn. J. Pharmacol. Jan 2000
PMID: 10874589 | Free Full Text

FOS Increases Bone Calcium and Magnesium in Rats

Abstract

Fructooligosaccharide consumption enhances femoral bone volume and mineral concentrations in rats.

We examined whether the enhanced mineral absorption resulting from fructooligosaccharide (FOS) consumption affects femoral bone structure and mineral concentrations, using histomorphometrical and X-ray microanalysis. Male Wistar rats (n = 16; 42 d old) were divided into two groups, a control group (n = 8) and a FOS group (5 g/100 g FOS in the diet, n = 8). After a 3-d adaptation period, constant amounts of calcium (95 mg/d) and magnesium (8 mg/d) were fed to the rats in each group, using a pair-feeding protocol. At age 60 d, a 3-d metabolic study was initiated. Calcium and magnesium absorptions were calculated. The rats were then killed, and the right femur was embedded in polyester resin. The distal metaphysis was sagittal-sectioned, and the middle of the diaphysis and neck were cross-sectioned. Calcium, magnesium and phosphorus concentrations in the three samples were then measured. Calcium and magnesium absorptions were significantly greater in FOS-fed rats. Trabecular bone volume at the metaphysis and bone volume at the neck of the femur in FOS-fed rats were also significantly greater than those in control rats. The mineral concentration (Ca, Mg and P) in each region of the bone surface was greater in FOS-fed rats. There was a significant relationship between absorbed calcium and calcium concentrations in bone (r = 0.722, P < 0.001), and a similar relationship was found for magnesium (r = 0.720, P < 0.001). These results suggest that the enhanced calcium and magnesium absorption due to FOS consumption might enhance femoral bone volume and mineral concentrations.

Takahara S, Morohashi T, Sano T, Ohta A…
J. Nutr. Jul 2000
PMID: 10867052 | Free Full Text