Consumption of an infant formula supplemented with long chain polyunsaturated fatty acids and iron metabolism in rats

This study examined the effects of an infant formula supplemented with long-chain polyunsaturated fatty acids (LCPUFA) on iron metabolism in rats. Three isocaloric diets were given to weaning rats during 28 days (150 g/kg fat): control diet (C), unsupplemented (F) and supplemented (FS) infant formula (as the only fat source) diets. Food intake and body weight evolution showed no significant differences between F and FS, but in both groups resulted lower compared to C. LCPUFA supplementation did not affect apparent iron absorption and retention nor the absorption and retention efficiencies, haemoglobin, serum iron, total iron binding capacity, haematocrit, liver and spleen iron. However, erythrocytic iron showed significant differences: FS>F>C. The results indicate that consumption of a diet containing an infant formula supplemented with LCPUFA does not affect iron metabolism in growing rats. Further studies based on the relationship between iron and lipid composition of erythrocytic membranes are required.     

Bioavailability of calcium,magnesium and phosphorus in rats fed probiotic,prebiotic and synbiotic powder follow‐up infant formulas and their effect on physiological and nutritional parameters

The effect of infant formulas supplemented with functional ingredients on calcium (Ca), magnesium (Mg) and phosphorus (P) bioavailability was investigated in rats. Seven follow‐up infant formulas containing probiotics (Bifidobacterium bifidum and Bifidobacterium longum), prebiotics (galactooligosaccharides at 12, 50 and 100 g kg^?1) or synbiotics (bifidobacteria and galactooligosacccharides) were administered to weanling rats for 30 days. A 3 day mineral balance was performed over three periods (8–10, 18–20 and 28–30 days) to monitor mineral apparent absorption and retention ratios and physiological and nutritional parameters. Feeding rats on infant formula‐based diets showed high feed efficiency (≥0.46). It was found that infant formulas supplemented with probiotics and/or prebiotics for 30 days increased Ca, Mg and P bioavailability in rats. Mineral apparent absorption and retention ratios were higher than 90% for Ca and P and 80% for Mg during the first balance period regardless of the infant formula used, but they decreased during the next two balance periods. Although it was not possible to select one infant formula as the best to improve mineral absorption, the 100 g kg^?1 prebiotic and 50 and 100 g kg^?1 synbiotic infant formulas were the most efficient at increasing Ca, Mg and P bioavailability compared with the control group. Copyright © 2006 Society of Chemical Industry     

New human milk fat substitutes from butterfat to improve fat absorption

A new human milk fat substitute (HMFS) was produced from butterfat. A 2-week’s feeding experiment was performed using three groups of rats with 10 wt.% fat in their feed; the fat was either (1) butterfat-based HMFS + long-chain polyunsaturated fatty acids (LCPUFA), (2) the reference oil + LCPUFA, or (3) the reference oil without LCPUFA. The apparent fat absorption after intake of butterfat-based HMFS (95.9% ± 1.8%) was significantly higher than the other two groups, indicating that much less calcium soap was formed after feeding butterfat-based HMFS. Calcium contents in urines and faeces from the two groups fed LCPUFA in their diet were lower than those without supplementation of LCPUFA, suggesting that LCPUFA could improve calcium absorption by reducing the calcium excretion. It can thus be concluded that the butterfat-based HMFS improves fat absorption, and supplementation of LCPUFA in the formula improves calcium absorption.     

Nutrition and magnesium absorption: a review.

This paper reviews the evidence that certain dietary components can affect intestinal absorption of magnesium. Increased intakes of protein and fructose improve apparent magnesium absorption (magnesium intake minus fecal excretion) in humans, whereas a lowering effect occurs with consumption of cellulose and phytate. Although dietary concentrations of lactose, fat, calcium and phosphate have clear effects on magnesium absorption in experiments with rats, the impact of these nutrients on magnesium absorption in humans remains unsettled. Mechanisms underlying the effects of dietary components on magnesium absorption in humans are generally poorly understood. A change in magnesium absorption not necessarily results in a change in magnesium retention. When consuming practical diets, the fall of apparent magnesium absorption caused by phytate and cellulose is generally compensated by increased magnesium intake due to high magnesium concentrations in phytate- and cellulose-rich products. Furthermore, to maintain homeostasis, urinary magnesium excretion will be raised after stimulation of apparent magnesium absorption and it will be lowered after impairment of apparent magnesium absorption. Thus, the effects of dietary components on magnesium absorption probably are critically important only at low intakes of magnesium. At low magnesium intakes, differences in magnesium absorption may be expected to influence magnesium retention and thus can either induce or abolish magnesium deficiency.     

Effects of diets containing oils from repeated frying on magnesium absorption

Olive oil, sunflower oil and palm olein were used in repeated potato fryings until the oils reached the limit of 25% of polar compounds allowed by law. Six groups of rats, over 28 days, were fed diets containing 8% of: olive oil; olive oil from 69 fryings; sunflower oil; sunflower oil from 48 frying; palm olein, and palm olein from 80 fryings. Body weight and food intake were monitored weekly, during days 21–28 faeces and urine were collected and finally blood and carcasses were also collected and stored. No significant differences were observed in food intake and body weight among the six groups of animals. The type of oil did not modify magnesium intake, the urinary and faecal excretion of this mineral nor its apparent absorption or retention. The consumption of oils from frying, however, induced an increase in apparent magnesium absorption due to a decrease in faecal magnesium excretion, but magnesium retention did not vary owing to the increase in urinary losses. Serum magnesium and magnesium contents and concentrations in carcasses were unaffected. Therefore, it was concluded that the consumption of used frying oils enhances magnesium absorption, independently from the type of oil, although magnesium retention is not affected due to a an elevation of urinary excretion. © 1999 Society of Chemical Industry     

Changes in calcium absorption and subsequent tissue distribution induced by Maillard reaction products: in vitro and in vivo assays

The effects of Maillard reaction products (MRP) from glucose–lysine and glucose–methionine on calcium bioavailability were studied by in vivo (rats) and in vitro (Caco‐2 cells) assays. Equimolar glucose/lysine and glucose/methionine mixtures (40% moisture) were heated (150 °C, 30 min) to prepare samples (GL30 and GM30, respectively). For 21 days, rats were fed a control diet (control group) or diets containing separately 3% of the heated mixtures (GL30 and GM30 groups, respectively). In the last week a calcium balance was performed, after which the animals were sacrificed and some organs and serum were removed to analyze calcium levels. A second balance was carried out throughout the experimental period to calculate global calcium retention (retained calcium during the entire 21 days). Unheated and heated samples were used for calcium transport experiments in Caco‐2 cells. Food intake and final body weight were lower in the GM30 group. Calcium fecal excretion decreased and digestibility increased in this group. Accordingly, increased calcium transport in Caco‐2 cells was found in the presence of the GM30 sample, when compared with the unheated sample. However, global calcium retention tended to decrease in the GM30 group, mainly owing to the lower food intake. Bone calcium concentrations decreased in the animals fed the MRP diets. The possible long‐term effects of MRP intake on calcium digestibility and bone calcium should be taken into account to avoid related diseases. Copyright © 2005 Society of Chemical Industry     

Mineral retention in three-week-old piglets fed goat and cow milk infant formulas

Goat milk and cow milk are commonly used in infant formula preparations and, as such, understanding the nutritional characteristics of infant formulas made from these milks is important. In this study, a goat milk infant formula was compared with an adapted (whey-enhanced) cow milk infant formula with respect to mineral absorption and deposition using the 3-wk-old piglet as a model for the 3-mo-old infant. Equal numbers of piglets (n = 8) were fed either the goat milk formula or the cow milk formula. The mineral composition of the prepared goat milk formula was higher than that of the prepared cow milk formula for most minerals, including calcium (75.1 vs. 56.7 mg/100 mL) but excluding iron, which was higher in the prepared cow milk formula (0.92 vs. 0.74 mg/100 mL). The amounts of calcium, phosphorus, and manganese absorbed by the piglets were significantly higher for the goat milk formula, whereas the amounts of zinc, iron, and magnesium absorbed were significantly higher for the cow milk formula. Apparent mineral absorption, relative to intake, was statistically higher in the cow milk formula for calcium and phosphorus, although the actual differences were very small (less than 1.3%). For copper, zinc, iron, and magnesium there was no significant difference between treatments in apparent mineral absorption, whereas for manganese, absorption was higher for the goat milk infant formula. The absolute mineral deposition was higher in piglets fed the goat milk formula for calcium, phosphorus, and manganese, whereas iron deposition was higher in the piglets fed cow milk formula. For all other minerals tested, there were no significant differences between treatments. The goat milk infant formula provided a pattern of mineral retention in the 3-wk-old piglet very similar to that of the adapted cow milk infant formula. The minor differences observed between the 2 appeared to be due to the different mineral contents of the 2 formulas.     

棕榈酸在三酰甘油中的位置分布对大鼠营养吸收的影响

研究了棕榈酸在三酰甘油中的不同位置分布对脂肪酸及矿质元素吸收的影响。以幼龄雄性Wistar大鼠为动物模型,将含不同比例sn-2位棕榈酸的脂肪原料添加到无脂饲料中,分别为:OPO(1,3-二油酸-2-棕榈酸甘油酯)结构脂肪,组成模拟OPO的混合植物油,含OPO的婴儿配方奶粉以及常规婴儿配方奶粉。饲料实验脂肪含量均为10%,各组sn-2位棕榈酸相对含量分别为45.40%、13.29%、48.04%、28.66%。喂养两周后,分析大鼠粪便中的脂质及钙、镁元素。结果显示,OPO组和OPO婴儿配方奶粉组的大鼠对脂肪的吸收显著高于另外两组,并且钙排泄较少。由此可得出结论:高含量的sn-2位棕榈酸可以促进大鼠对脂肪的吸收,减少脂肪酸皂的形成,并能改善对钙的吸收。     

Nutritional Evaluation with an Animal Model of Cottage Cheese Fortified with Calcium and Guar Gum

Apparent absorption of calcium by rats from cottage cheese was very efficient under the conditions tested. However, overall calcium retention and, to a lesser extent, bone calcium content increased with each increment in dietary calcium. Despite sensitivity of the model to variation in calcium intake, no effect of guar gum on calcium utilization was noted. Increasing the calcium added to cottage cheese increased phosphorus retention, did not antagonize utilization of magnesium and zinc, and only slightly decreased iron utilization in rats.     

Influence of hydrocortison acetate on the evolution of the nutritive utilization of calcium and phosphorus and their contents on the longissimus dorsi muscle during gestation in the rat

The evolution of the nutritive utilization and plasma and muscular content of calcium and phosphorus in rats is studied, as well as the influence that hydrocortisone acetate has (4 mg/100 g weight and day), on them. In pregnant rats injected with saline solution, the retention of calcium is higher on the days 15-18 as a consequence of the increase on the net absorption of the cation. The balance of phosphorus reaches its maximum hight on days 18-21 of gestation, due to the decrease of the urinary excretion during these days. The administration of hydrocortisone acetate to pregnant rats originate a decrease of the net absorption and an increase of the urinary excretion of calcium and phosphorus, which leads to significantly lower balances than those of animals injected with saline solution. The hormone maintains the animals in a negative balance of phosphorus until day 18 of gestation. Besides, it impedes the high retention of calcium which is found with the control pregnant rats on days 15-18. In general, the content in calcium and phosphorus by gram of dry matter of Longissimus dorsi muscle is not modified during gestation. From day 9 of the treatment with hydrocortisone acetate a significant decrease of calcium and phosphorus of the muscle is observed, that in calcium is the more marked the more the treatment is prolonged. This effect seems to be due to the catabolic action of the hormone.     

Intake of unused palm olein and palm olein used in frying does not affect calcium and phosphorus bioavailability in rats

Palm oil is widely used as a cooking medium. This study was undertaken to examine whether extensive use leading to the formation of polar compounds has any effect on calcium and phosphorus balances. Three isocaloric diets containing 8% olive oil (O), palm olein (P) and palm olein from 80 repeated potato frying uses (PF) without turnover, and which nearly reached the limit of 25% polar compounds allowed by law, were prepared and given to three groups of growing rats during a study period of 28 days. Body weight and food intake were monitored and faeces and urine were collected to calculate calcium and phosphorus balances during the last week of the study. At the end of the experiment the animals were killed and their livers, serum and carcases stored. No differences were observed between food intake, body weight and food efficiency of rats which consumed palm olein, whether unused or used in frying, and the control group (O). The liver mass index was higher in PF than O rats. No significant differences were observed in apparent absorption and retention of calcium and phosphorus. Faecal calcium (p = 0.065) and the percentage of phosphorus absorbed (p = 0.084) showed a tendency to increase in rats fed diets with both unused and used palm olein and could be due to the known higher affinity of fat for Ca than P. No variations in serum calcium and carcase calcium and phosphorus levels were seen. The conclusion of this study was that consumption of palm olein, whether unused or used in frying, does not alter calcium and phosphorus bioavailability. © 2000 Society of Chemical Industry     

Calcium bioavailability in human milk,cow milk and infant formulas—comparison between dialysis and solubility methods

The percentages of total, soluble and dialysable calcium of human milk, cow milk and milk and soy based infant formulas were determined in order to detect possible differences in the calcium bioavailability of the samples. For this purpose an in vitro method was applied to these four calcium sources. The ranking of the analysed samples in terms of calcium bioavailability depends on the criteria applied. Calcium ranked dialysis percentage was: cow milk>human milk>soy based formula>milk based formulas. Calcium ranked solubility percentage was: human milk>cow milk>soy-based formula>milk-based formulas. Comparison of the results of the in vitro assay with the information available on in vivo calcium absorption showed that the total soluble calcium contents agree with the in vivo absorption values better than with calcium dialysis percentages.     

Influence of hydrocortisone acetate on the magnesium metabolism during pregnancy in rats

The influence of hydrocortisone acetate i.m. administered (4 mg/100 g of body weight and day) to pregnant rats, on magnesium nutritive utilization and bone magnesium content in the mothers and its possible repercussions on newborn Mg content are studied. Hydrocortisone acetate treatment significantly reduces Mg content in the litters, which can be explained on the basis of a significant decrease in both the magnesium absorption and retention by the hormone-treated mothers. The mobilization of femoral magnesium and the increase in the urinary excretion of the cation provoke a reduction in magnesium retention in the treated mothers.     

Effect of fructooligosaccharide on nutritional parameters and mineral bioavailability in rats

The effect of fructooligosaccharide on protein digestibility and mineral absorption was studied in rats fed diets containing 5 g kg^?1 fructooligosaccharide, 5 g kg^?1 cellulose/fructooligosaccharide (1:1) or 5 g kg^?1 cellulose as a source of dietary fibre. Addition of cellulose/fructooligosaccharide or fructooligosaccharide to the diet did not significantly modify the daily food intake and food efficiency. However, the fructooligosaccharide‐fed group showed a significant decrease in body weight gain compared with cellulose‐fed groups. Faecal excretion was significantly lower when there was fructooligosaccharide intake, despite there being no significant differences in cellulose‐fed groups. Intake of fructooligosaccharide produced an increase in caecal content and an enlargement of the caecal wall. This trophic effect could be attributed to short‐chain fatty acids produced from the anaerobic fermentation of fructooligosaccharide by intestinal bacteria. Cellulose/fructooligosaccharide enhanced the apparent absorption and apparent retention of Ca, Mg, Zn and Fe. Fructooligosaccharide‐fed rats experienced an increase in apparent absorption and apparent retention of Mg compared with cellulose‐fed rats. Fructooligosaccharide intake at the lowest dose was enough to provide a desirable effect on mineral bioavailability in rats without any modification of nutritional parameters. © 2002 Society of Chemical Industry     

Calcium Bioavailability from High Oxalate Vegetables: Chinese Vegetables, Sweet Potatoes and Rhubarb

Absorption of calcium from high calcium vegetables endogenously labeled with ⁴⁵Ca was studied in premenopausal women using a randomized cross over design. Chinese (C.) vegetables are a major source calcium, but the bioavailability is unknown and likely affected by oxalic acid content. Calcium absorption from Chinese vegetables, sweet potatoes, and rhubarb, was compared to milk at the same calcium level for calculation of an absorption index. Calcium absorption generally reflected oxalic acid content. Calcium absorption index (X±SEM) was least for C. spinach (0.257±0.0228) and rhubarb (0.235±0.0233), intermediate for sweet potatoes (0.423±0.0255), and highest for C. mustard greens (1.097±0.0532) and C. cabbage flower leaves (1.097±0.0532).     

微生态补钙制剂的生物利用研究

补钙制剂的生物利用率是评价补钙效果的重要指标。以KM种健康小鼠为模型,饲喂不同钙源及钙含量的饲料,测定饲料消耗量、粪钙、尿钙、骨钙和血钙,计算钙的表观吸收率及存留率,并与对应剂量的碳酸钙组对比,评价微生态补钙制剂的生物利用情况。结果表明：微生态补钙制剂低剂量组和标准剂量组的骨钙含量与相同水平的碳酸钙对照组比较差异显著(P＜0.05),钙的表观吸收率明显高于对应碳酸钙剂量组(P＜0.01);微生态补钙制剂组与碳酸钙对照组相比,血钙水平差异不显著(P＞0.05),但均高于碳酸钙对照组。表明微生态补钙制剂生物利用率高,是一种理想的补钙制剂。     

Maillard reaction products consumption: Magnesium bioavailability and bone mineralization in rats

The aim of this study was to analyze the influence of the consumption of Maillard reaction products (MRP), derived from glucose-lysine and glucose-methionine mixtures heated for 90 minutes, on magnesium bioavailability and tissue concentration. Magnesium balances were performed in rats. Subsequently, the animals were sacrificed and certain organs removed to analyze the magnesium contents. Glucose-methionine MRP induced increases in magnesium fractional absorption in the last week of the assay (69.2 ± 2.9%) compared with the control group (59.4 ± 1.3%), although no variations in magnesium bioavailability during the total period balance were found. The intake of both MRP assayed seemed to increase renal and hepatic magnesium, decrease calcium bone concentration and mask the positive effect of the free amino acids still present in the samples on bone magnesium. The results show that MRP dietary consumption could lead to changes in bone mineralization. The long-term effects should be more deeply studied to predict possible implications for bone health.     

膳食纤维对大鼠钙平衡及骨生物力学性能的影响

目的：研究不同结构的膳食纤维对钙平衡及生物力学性能的影响。方法：以大鼠作为动物模型分组饲养,分别饲喂含有50 g/kg麦麸、纤维素、木聚糖、果胶、菊粉、魔芋胶及其混合物的饲料。利用原子吸收光谱法检测饲料、粪便、尿样、股骨中钙含量;利用电解质分析仪测定血清中的总钙、游离钙、结合钙浓度;用三点弯曲法检测股骨的最大载荷。比较摄入不同膳食纤维大鼠钙吸收、血钙水平、尿钙流失、钙保留率、骨钙含量、骨的生物力学性能等参数的差异。结果：在钙吸收率方面,麦麸、纤维素组高于木聚糖、果胶、菊粉、魔芋组,其中木聚糖和魔芋组与麦麸组具有极显著差异（P<0.01）;在尿钙日排出量方面,木聚糖和纤维素组低于其余各组;在钙保留率方面,果胶组最低,处于负钙平衡;在血清钙水平方面,麦麸组血清游离钙浓度和其余实验组没有显著性差异（P>0.05）,但麦麸组结合钙和总钙浓度均高于其他各组;在骨钙含量和骨生物力学性能方面,果胶组明显低于其他各组,木聚糖组的骨最大载荷高于其他各组。结论：麦麸和纤维素等低发酵型膳食纤维的肠道钙吸收率高于木聚糖、果胶、菊粉、魔芋等高发酵型膳食纤维;木聚糖有助于提高大鼠骨生物力学性能;不同膳...     

Prebiotics enhance magnesium absorption and inulin-based fibers exert chronic effects on calcium utilization in a postmenopausal rodent model

Abstract: Age‐related changes in calcium metabolism play a role in the development of osteoporosis. A 4‐wk feeding study was conducted in 5‐mo‐old ovariectomized (OVX) Sprague‐Dawley rats to assess the effect of various dietary fibers on mineral metabolism and bone health parameters. There were 6 treatment groups: sham‐Control, OVX‐Control, OVX rats receiving daily estradiol (E₂) injections, and OVX rats receiving an AIN‐93M diet supplement with either an inulin‐based fiber (Synergy1® or Fruitafit HD®) or a novel fiber (polydextrose) at 5% wt. of diet. Calcium and magnesium metabolic balances were performed after early (3 d) and late exposure (4 wk) to dietary treatments. Rats receiving polydextrose had significantly higher net calcium absorption efficiency and retention than all control groups and a trend (P≤ 0.10) for higher calcium absorption when compared to inulin‐based fibers after early exposure but the advantage did not persist over long‐term exposure. The inulin‐based fibers had positive chronic effects on calcium metabolism that were related to changes in the gut, that is, production of short chain fatty acids and higher cecal wall weights. All fibers improved magnesium absorption and retention in early and late metabolic balances; effects on magnesium metabolism were more pronounced than for calcium. Practical Application: Steady growth in US middle‐aged and elderly populations has led to higher incidences of several chronic diseases including osteoporosis, a bone disease that primarily affects postmenopausal women. Recent research suggests that certain dietary fibers (prebiotics) enhance mineral absorption and may impart bone health benefits. This work examines the impact of prebiotic supplementation on mineral metabolism and bone health using a postmenopausal rat model. Study findings will aid future investigations in ascertaining the factors related to potential bone health benefits of prebiotic which will aid in developing an effective prebiotics food product/supplement that will address the bone health needs of consumers.     

Effects of probiotic,prebiotic and synbiotic follow‐up infant formulas on large intestine morphology and bone mineralisation in rats

The effects of powder functional follow‐up infant formulas on the morphology of the large intestine and the bone mineral content in rats were investigated. Infant formulas were supplemented with probiotics (Bifidobacterium bifidum and Bifidobacterium longum), prebiotics (galacto‐oligosaccharides (4′‐GOS) at 12, 50 and 100 g kg^?1) or synbiotics (bifidobacteria and 4′‐GOS) and administered to seven groups of weanling rats over 30 days. After sacrificing the animals, the caecum and colon were removed and the luminal content pH and the crypt depth and cell density within the epithelial layer were measured. Results showed that groups fed synbiotic diets had significantly (P < 0.05) lower caecal and colonic content pH values compared with the control group. However, no test diet significantly modified the crypt depth or cell density in the caecum. In contrast, all seven test diets significantly increased (P < 0.05) the crypt depth in both the proximal and distal portions of the colon. There was a high correlation (Pearson correlation coefficient 0.870) between caecal and colonic content pH values. On the other hand, colonic content pH was negatively correlated with crypt depth in both the proximal and distal colon and with cell density in the distal colon. The authors previously reported increases in calcium, magnesium and phosphorus absorption using the same infant formulas. In the present study it was concluded that the increase in calcium absorption took place in the distal colon whereas magnesium absorption increased in both the proximal and distal colon, and their contents (especially that of calcium) increased in both the femur and tibia. Copyright © 2007 Society of Chemical Industry