Fatty acid balance studies in preterm infants fed formula milk containing long-chain polyunsaturated fatty acids (LCP) II

A milk formula (Prematil-LCP) containing long-chain polyunsaturated fatty acids (LCP) and with a fatty acid profile closely resembling breast milk has recently been introduced for preterm infants. A double-blind randomized controlled trial was performed comparing fatty acid absorption from Prematil-LCP (n = 10) and standard Prematil (n = 10). Formula-fed preterm infants underwent 3 d fat balances (once full enteral feeds were established) along with a parallel human milk fed group (n = 11). Plasma samples were taken on the last day. Median total fat excretion (absorption, %) was 2.34 g kg (82.0), 2.64 g kg (82.9) and 1.65 g kg (87.8) with Prematil, Prematil-LCP and human milk feeding, respectively. This reflected differences in the excretion and absorption of long-chain saturated fatty acids. All groups excreted detectable LCP. LCP disappearance was higher in infants fed human milk than in those fed Prematil-LCP, particularly for n -6 LCP (p <0:01). Nevertheless, excreted LCP equated to <30% dietary intake, with Prematil-LCP feeding. Plasma lipid fatty acid composition reflected differences in dietary LCP intake.     

Neonatal nutrition with enriched human milk. EOPROTIN 60 in comparison with human albumin]

The influence of feeding fresh human milk supplemented either with EOPROTIN (n = 13) or human albumin (n = 15) on biochemical parameters and growth were studied in preterm infants with gestational ages below 32 weeks p.m. up to the 42nd day of postnatal life. In both feeding groups the intakes of protein, energy and electrolytes were similar. The serum concentrations of bile acids, alpha-amino-nitrogen and prealbumin, the renal excretion of total nitrogen, alpha-amino-nitrogen, urea and ammonia as well as the growth in weight and length were studied in all infants. The supplementation of the fresh human milk with EOPROTIN results in significant lower serum concentrations of alpha-amino-nitrogen (1.56 +/- 0.21 vs 2.03 +/- 0.27 mmol/l; p less than 0.01), higher serum concentrations of prealbumin (89.8 +/- 20.3 vs 72.7 +/- 13.3 mg/l; p less than 0.02), and lower urinary excretion of total nitrogen (7.4 +/- 0.9 vs 8.9 +/- 1.1 mmol/kg/day); if compared to the results found in the infants fed human albumin supplemented human milk. The higher nitrogen retention in the EOPROTIN than in the human albumin fed infants was associated by a significant higher growth in weight (16.6 +/- 1.4 vs 13.7 +/- 1.9 g/kg/day; p less than 0.01) as well as in length (1.02 +/- 0.08 vs 0.87 +/- 0.1 cm/week; p less than 0.01). The results indicate that the bioavailability of EOPROTIN is higher than that of human albumin. The observed differences in the nutritional response between the two human milk supplements may be based on differences in the amino acids composition which is in EOPROTIN adapted to the nutritional available part of the protein in human milk.     

Serum phenylalanine in preterm newborns fed different diets of human milk

ObjectiveTo evaluate phenylalanine plasma profile in preterm newborns fed different human milk diets.MethodsTwenty-four very-low weight preterm newborns were distributed randomly in three groups with different feeding types: Group I: banked human milk plus 5% commercial fortifier with bovine protein, Group II: banked human milk plus evaporated fortifier derived from modified human milk, Group III: banked human milk plus lyophilized fortifier derived from modified human milk. The newborns received the group diet when full diet was attained at 15 ± 2 days. Plasma amino acid analysis was performedon the first and last day of feeding. Comparison among groups was performed by statistical tests: one way ANOVA with Tukey's post-test using SPSS software, version 20.0 (IBM Corp, NY, USA), considering a significance level of 5%.ResultsPhenylalanine levels in the first and second analysis were, respectively, in Group I: 11.9 ± 1.22 and 29.72 ± 0.73; in Group II: 11.72 ± 1.04 and 13.44 ± 0.61; and in Group III: 11.3 ± 1.18 and 15.42 ± 0.83 μmol/L.ConclusionThe observed results demonstrated that human milk with fortifiers derived from human milk acted as a good substratum for preterm infant feeding both in the evaporated or the lyophilized form, without significant increases in plasma phenylalanine levels in comparison to human milk with commercial fortifier.     

Weight gain composition in preterm infants with dual energy X-ray absorptiometry

Whole body composition was investigated using dual energy x-ray absorptiometry in 54 healthy preterm infants, birth weight < 1750 g, who were fed fortified human milk (n = 20) and preterm formula (n = 34) when full enteral feeding was attained and then again 3 wk later at around the time of discharge. Weight gain composition was calculated from the difference between the earlier and later measurement. The minimal detectable changes in whole body composition over time according to the variance of the population (within groups of 20 infants) and the minimal detectable changes according to the dietary intervention (between two groups of 20 infants) were determined at 5% significance and 80% power. Whole body composition was similar in the two groups at the initial measurement, but all the measured variables differed at the time of the second measurement. Formula-fed infants showed a greater weight gain (19.9 +/- 3.2 versus 15.9 +/- 2.2 g.kg(-1).d(-1), p < 0.05), fat mass deposition (5.1 +/- 1.9 versus 3.3 +/- 1.3 g.kg(-1).d(-1), p < 0.05), bone mineral content gain (289 +/- 99 versus 214 +/- 64 mg.kg(-1).d(-1), p < 0.05), and increase in bone area (1.6 +/- 0.4 versus 1.3 +/- 0.3 cm(2).kg(-1).d(-1), p < 0.05) compared with the fortified human milk group. From these data, a minimal increase from the first measurement of 111 g lean body mass, 68 g fat mass, and 3. 1 g bone mineral content is needed to be detectable in a longitudinal study that includes 20 infants. For significance between two groups of 20 infants around the time of discharge, dietary intervention needs to achieve minimal differences of 160 g lean body mass, 86 g fat mass, and 4.1 g bone mineral content. With respect to weight gain composition, the minimal differences required to reach significance are 2.1 g.kg(-1).d(-1) for gain in lean body mass, 1.2 g.kg(-1).d(-1) for gain in fat mass, and 76 mg.kg(-1). d(-1) for gain in bone mineral content. We conclude that dual energy x-ray absorptiometry allows evaluation of the effects of dietary intervention on whole body and weight gain composition in preterm infants during the first weeks of life.     

Growth, biochemical status, and mineral metabolism in very-low-birth-weight infants receiving fortified preterm human milk

We compared the growth, biochemical status, and mineral status of 30 very-low-birth-weight infants randomly assigned to receive preterm human milk (Group I, 10 infants) from their own mothers, fortified preterm human milk (Group II, 8 infants), or a high-caloric-density premature formula (Group III, 12 infants). Added to the infant's own mother's milk, a human milk fortifier at full strength provided additional protein (60:40 whey/casein, 0.7 g/dl), calories (4 kcal/oz), and minerals. Volume of intake, feeding tolerance, and complications were similar in the three groups. Infants receiving fortified preterm human milk showed growth, biochemical status, and mineral status similar to those receiving high-caloric-density formula, but infants receiving fortified preterm human milk grew faster (12.0 +/- 3.2 vs. 8.9 +/- 1.1 days/300 g, p less than 0.05), had higher serum protein (4.6 +/- 0.5 vs. 4.2 +/- 0.2 g/dl, p less than 0.05), and tended to have better mineral status (higher serum calcium, lower alkaline phosphatase, and higher serum phosphorus, none individually significant) than infants receiving preterm human milk alone. This study supports previous observations that fortified preterm human milk provides nutritional advantages for very-low-birth-weight infants.     

Influence of feeding formula and breast milk fortifier on lymphocyte subsets in very low birth weight premature newborns

BACKGROUND: It is well known that breast-feeding protects the newborn from infectious diseases. This is especially important for very low birth weight preterm infants, whose immune systems are immature. In this study we investigated how a milk fortifier and replacement formula affected lymphocyte subsets in preterm infants. METHOD: The study assessed the effects of different types of feeding (human milk, n = 14; fortified human milk, n = 16; formula, n = 14) on lymphocyte subsets in 44 very low birth weight preterm infants. For each baby, two consecutive blood samples were collected 7-10 days apart during the full enteral feeding period. For each sample, the percentages of CD3+ (pan-T), CD19+ (B-cell), CD4+ (T-helper), CD8+ (T-suppressor), and CD3-CD16/56+ (natural killer cell) lymphocytes were measured in a flow cytometer, and the absolute count for each subset was calculated based on the total lymphocyte count. Within each feeding group, the absolute numbers of each lymphocyte subset in the two consecutive samples were compared. Also, the mean absolute counts for each cell type were compared among the 3 groups for the first set of blood samples, and the same comparisons were made for the second set. RESULTS: The mean number of CD3-CD16/56+ cells in the formula-fed infants was significantly lower than the corresponding means in the groups fed human milk alone and fortified human milk (p = 0.037). CONCLUSION: The findings suggest that babies fed formula have different lymphocyte subset compositions than those fed breast milk or fortified breast milk.     

Supplementation with human milk protein improves growth of small premature infants fed human milk

We investigated the influence of human milk protein and medium-chain triglyceride supplementations of human milk feedings on the growth of very low birth weight infants during their first weeks of life. A group of 44 preterm infants with birth weights of less than 1,520 g and a mean gestational age of 30.3 weeks was randomly divided into four groups to receive plain human milk or human milk supplemented with human milk protein (0.9 g/dL), with medium-chain triglycerides (1 g/dL), or with both. The medium-chain triglyceride oil supplementation did not influence the growth of these infants. The infants given supplementary protein gained weight faster during weeks 4 to 6 than those without (18.5 +/- 0.7 v 15.1 +/- 0.6 g/kg/d; mean +/- SEM; P = .001). After 4 weeks of age the infants given supplementary protein had a mean weight gain equal to the mean intrauterine rate, in contrast to the infants of the other groups, who grew more slowly until age 6 weeks. Furthermore, we found a correlation between serum albumin concentration and weight gain during the seventh week of life (P = .018). The length growth velocity for the infants with protein supplementation was 0.99 +/- 0.06 cm/wk (mean +/- SEM) and for those without 0.83 +/- 0.05 cm/wk (P = .043). There was no difference in growth of head circumference between the groups. We conclude that human milk protein supplementation improves the growth of small premature infants fed human milk, and that the protein concentration of bank milk is insufficient for their adequate growth.     

The effect of prenatal consultation with a neonatologist on human milk feeding in preterm infants

OBJECTIVE: To study the effect of prenatal consultation (PC) with a neonatologist on the incidence and duration of human milk feeding (HMF) in preterm infants. DESIGN/METHODS: A retrospective matched case-control study was preformed at a perinatal centre. Study infants were preterm infants (23-35 wk) whose mothers had received PC emphasizing the importance of HMF. Control infants were matched by birthweight, gestational age and multiplicity. RESULTS: Each group included 29 mothers and 46 preterm infants. Mean gestational age was 30.1 +/- 3 wk in both groups. Mean birthweight was 1329 +/- 489 (PC) and 1334 +/- 441 g (control). PC infants received HMF for significantly longer, both in the hospital and after discharge (hospital: PC 37 +/- 34 d vs control 15 +/- 19 d, p = 0.001; discharge PC 60 +/- 57 d vs control 21 +/- 32 d; p = 0.0001). No significant difference in neonatal morbidity was detected between the groups. CONCLUSIONS: PC is associated with significantly longer HMF in preterm infants, both in hospital and after discharge.     

Zinc homeostasis in premature infants does not differ between those fed preterm formula or fortified human milk

The objectives of this study were to compare zinc homeostasis in premature infants enterally fed with either preterm infant formula or fortified human milk; to examine interrelationships of variables of zinc homeostasis; and to examine the findings in relation to estimated zinc requirements of preterm infants. Zinc homeostasis was studied in 14 infants (8 male), with mean gestational age of 31 wk and birth weight appropriate for gestational age, who were exclusively fed either preterm formula (n = 9) or own mother's milk with human milk fortifier (n = 5). Zinc stable isotopes were administered intravenously ((70)Zn) and orally as an extrinsic label ((67)Zn) over multiple feeds for determination of fractional absorption by dual isotope tracer ratio in urine; endogenous fecal zinc was determined by isotope dilution; and exchangeable zinc pool (EZP) size was estimated from linear regression of log-transformed urine (70)Zn enrichment data. Results indicated no significant differences in the variables of zinc homeostasis between the feeding groups; data for all subjects were thus combined. Mean (+/- SD) fractional absorption was 0.26 +/- 0.07; net absorbed zinc 0.43 +/- 0.25 mg/d (0.31 +/- 0.19 mg/kg/d). Mean EZP was 20 +/- 10 mg/kg, and was positively correlated with total absorbed zinc and with net absorbed zinc. Feeding type and total absorbed zinc were significantly related to daily weight gain (p = 0.003). Current zinc intakes from fortified human milk or formula are associated with acceptable weight gain, but whether the observed net zinc absorption was optimal in the human milk group cannot be definitively determined from these data.     

Growth of very low birth weight infants on varying amounts of human milk protein

In a double-blind, randomized study, 28 healthy, growing very low birth wt, appropriate-for-gestational-age infants were fed human milk, preferably mother's own, fortified daily with human milk protein and/or human milk fat. The infants entered the study when they were stable on complete enteral intakes of 170 mL/kg/d (mean age = 19 d). The study lasted for a mean of 4 wk. Samples from all the milks were collected daily, and intakes of protein, fat, carbohydrates, energy, and electrolytes were calculated weekly during the whole study period. Protein intakes ranged from 1.7 to 3.9 g/kg/d, and energy intakes from 100 to 150 kcal/kg/d. Wt and length gain in the nonprotein-enriched groups were 15.6 +/- 2.7 g/kg/d (mean +/- SD) and 0.88 +/- 0.17 cm/wk; the corresponding figures for the protein-enriched groups were 20.2 +/- 2.1 g/kg/d and 1.24 +/- 0.14 cm/wk. There was a strong correlation between protein intake and growth in wt and length up to an intake of about 3 g/kg/d; more protein did not result in increased growth. The same was true for energy intake, with a maximal growth rate at an intake of about 120 kcal/kg/d. A protein intake of more than 3 g/kg/d resulted in a growth rate equal to or higher than the estimated intrauterine growth rate. Some infants fed mature banked human milk alone had a poor growth. Sodium intake was low, ranging from 1.5 to 2.6 mmol/kg/d. No correlation was found between sodium intake and growth rates.     

Improved growth of preterm infants receiving mother's own raw milk compared with pasteurized donor milk

Aim: To determine whether growth, feeding tolerance and infectious events of preterm infants is related to the proportion of intake of mother’s own raw milk (maternal milk) versus pooled pasteurized banked breast milk (donor milk). Methods: This is a prospective observational study of 55 premature infants born less than 32 weeks of gestational age admitted to the neonatal intensive care unit at the Children’s Hospital of Toulouse during two 6‐month periods from 2003 to 2005. Enrolled infants were exclusively on enteral feeds with maternal milk ± donor milk. Results: Mean gestational age was 28.6 weeks (SD 1.5) and mean birth weight 1105 grams (SD 282). During the time of exclusively breast milk feeds, weight gain (g/kg/day) was correlated to the proportion of maternal milk consumed (p = 0.0048, r = 0.4). Necrotizing enterocolitis was inversely correlated to the amount of maternal milk. The amount of maternal milk did not impact on infectious events. Conclusion: Mother’s own raw milk improves weight gain compared with donor milk in preterm infants. Lactation strategies should be sought that helps mothers to increase their milk production.     

Urinary excretion of lactose and oligosaccharides in preterm infants fed human milk or infant formula

At present, not much is known about the absorption and metabolism of human milk (HM) oligosaccharides in term and preterm infants. We investigated the renal excretion of lactose and complex oligosaccharides in preterm infants fed HM ( n = 9, mean actual body weight 2290 g) or a cow's milk-based infant formula ( n = 9, mean actual body weight 2470 g). We found that the renal excretion of lactose in HM-fed infants was slightly lower than in formula-fed infants (14.0 ± 7.4 versus 20.4 ± 8.7 mg kg^-1 day^-1, mean ± SD). The excretion of neutral sugars deriving from oligosaccharides was similar in HM-fed and formula-fed infants (3.8 ± 2.1 versus 2.9 ± 0.9mgkg^-1 day^1-); the difference between means was not statistically significant. The separation and characterization of oligosaccharides by high-pH anion exchange chromatography with pulsed amperometric detection (HPAE-PAD) and subsequent analysis by fast atom bombardment-mass spectrometry (FAB-MS) revealed a more complex pattern in HM-fed infants compared to the formula-fed group. Lactose-derived oligosaccharides characteristic for HM (e.g lacto- N -tetraose, and lacto- N -fucopentaoses I and II) were excreted in HM-fed but not in formula-fed infants. These results indicate that nutrition has a significant impact on the oligosaccharide composition in urine of preterm infants.     

A multicenter long-term safety and efficacy trial of preterm formula supplemented with long-chain polyunsaturated fatty acids

BACKGROUND: The tissue accretion of long-chain polyunsaturated fatty acids is compromised in infants born prematurely. Human milk contains long-chain polyunsaturated fatty acids, but most preterm infant formulas do not. The long-term effects of preterm formula supplemented with arachidonic acid and docosahexaenoic acid, in proportions typical of those in human milk, were therefore investigated. METHODS: In this double-blind, randomized study, 288 preterm infants received experimental formula (n = 77), unsupplemented (control) formula (n = 78), or human milk (n = 133) until 48 weeks postconceptional age (PCA). Term formula, without supplemental long-chain polyunsaturated fatty acids, was administered from 48 to 92 weeks PCA to formula-fed infants and to infants weaned from human milk. Anthropometric and fatty acid data were assessed by using analysis of variance. RESULTS: At 92 weeks PCA, no statistically significant anthropometric measurement differences were found except for midarm circumference, which was smaller in human milk-fed infants than in those fed formula. Phospholipid concentrations were similar in the experimental and human milk-fed groups, and docosahexaenoic acid levels were significantly greater than in the control group. The types and incidences of adverse events were similar among the feeding groups. CONCLUSIONS: The results of this study demonstrate the efficacy and long-term safety of preterm formula supplemented with long-chain polyunsaturated fatty acids.     

Macronutrient and energy content of breast milk of mothers delivering prematurely

The protein, lactose, fat and energy contents of the fore-milk of mother with term (n=23) and preterm (n=29) infants were estimated on postpartum days 3, 7, 14 and 21. During the first 4 weeks of lactation, the mean (±SD) energy (Kcal/dl), protein (g/dl), fat (g/dl) and lactose (g/dl) levels of the preterm milk were: 56.39 (±7.99), 2.17 (±0.66), 2.30 (±0.48) and 5.78 (±0.99), respectively. The same for term milk were: 59.39 (±8.30), 1.99 (±0.70), 2.48 (±0.53) and 6.24 (±1.08), respectively. The differences in composition between the term and preterm milk were not significant. The composition of breast milk showed changes over the first 3 weeks of lactation. With increasing post-partum days, there was a decline in protein content while fat, lactose and energy contents increased. These trends were more pronounced for preterm milk than term milk. The macronutrient composition and energy estimates of preterm breast milk of Indian mothers in this study may be useful for calculation of nutritional intake by premature neonates fed on expressed breast milk.     

Prebiotic concept for infant nutrition

In the neonatal period, the intestine is colonised in a stepwise process that depends on mode of delivery, environmental factors, bacterial interactions, and the host itself resulting in a colonisation with a complex heterogeneous bacterial flora. Oligosaccharides have been identified as an important prebiotic factor of human milk As long as analogues of human milk oligosaccharides are not available now and in the near future it is aimed to resemble the prebiotic effect of human milk by oligosaccharides from available sources. In the present study in preterm infants, a mixture of 90% galacto-oligosaccharides and 10% fructo-oligosaccharides has been tested. The mixture of GOS/FOS was composed to mimic the molecule size distribution of human milk oligosaccharides. Microbiological analysis of the faces was performed before and 7, 14, and 28 days after start of supplementation and stool characteristics have been recorded. Maltodextrin was used as placebo and infants fed human milk have been used as reference. After a 28 days feeding period, the number of bifidobacteria of the group fed the oligosaccharide supplemented formula was in the upper range of the reference group whereas the numbers of the group fed the formula supplemented with the placebo were in the lower range of the reference group (placebo: 7.9 +/- 0.83 and GOS/FOS mixture: 10,0 +/- 2.05 log 10 CFU/g wet stool; reference (M +/- SD): 7.14-10.7 log 10 CFU/g wet stool). Stool characteristics in the group fed the supplemented formula were close to those found in the human milk fed infants. In summary, supplementation of a preterm formula with a mixture of galacto- and fructo-oligosaccharides has a stimulating effect on the growth of bifidobacteria in the intestine and results in more frequent produced and softer stools. Thus, prebiotic mixtures such like the studied oligosaccharide mixture might help in improving intestinal tolerance to enteral feeding in preterm infants.     

Individualized protein fortification of human milk for preterm infants: comparison of ultrafiltrated human milk protein and a bovine whey fortifier.

BACKGROUND: To improve the nutritional management of pre-term infants, a new individualized human milk fortification system based on presupplementation milk protein analyses was evaluated. METHODS: In an open, prospective, randomized multicenter study, 32 healthy preterm infants (birth weights, 920-1750 g) were enrolled at a mean of 21 days of age (range, 9-36 days) when tolerating exclusive enteral feedings of 150 ml/kg per day. All infants were fed human milk and were randomly allocated to fortification with a bovine whey protein fortifier (n = 16) or ultrafiltrated human milk protein (n = 16). All human milk was analyzed for protein content before fortification with the goal of a daily protein intake of 3.5 g/kg. During the study period (mean, 24 days) daily aliquots of the fortified milk were obtained for subsequent analyses of the protein content. RESULTS: Both fortifiers were well tolerated, and growth gain in weight, length, and head circumference, as well as final preprandial concentrations of serum urea, transthyretin, transferrin, and albumin were similar in both groups. The ultimate estimated protein intake was equivalent in both groups (mean 3.1+/-0.1 g/kg per day). Serum amino acid profiles were similar in both feeding groups, except for threonine (significantly higher in the bovine fortifier group) and proline and ornithine (significantly higher in the human milk protein group). CONCLUSIONS: Protein analyses of the milk before individual fortification provides a new tool for an individualized feeding system of the preterm infant. The bovine whey protein fortifier attained biochemical and growth results similar to those found in infants fed human milk protein exclusively with the corresponding protein intakes.     

Hindmilk and weight gain in preterm very low-birthweight infants

BACKGROUND: Feeding of own mother's milk to preterm very low-birthweight infants often results in suboptimal weight gain in these infants for whom energy requirements are high but in whom volume tolerance is limited. Therefore the purpose of the present paper was to investigate the effect of selective hindmilk feeding on the growth of preterm very low-birthweight babies. METHODS: Preterm very low-birthweight babies admitted into the Special Care Baby Unit of the Jos University Teaching Hospital, Nigeria between April 2000 and July 2001 were randomized to hindmilk and composite breast milk feeding for 2 weeks. End-points were weight, occipitofrontal head circumference and length. RESULTS: For small-for-gestational-age babies, the infants fed on hindmilk gained weight at a mean rate of 12.92 +/- 10.95 g/kg per day as compared with a mean rate of 5.01 +/- 17.37 g/kg per day for their controls on composite milk (P < 0.0001). For appropriate-for-gestational-age babies, the mean rate of weight gain for the hindmilk group was 12.99 +/- 10.75 g/kg per day while that for their controls on composite milk was 8.29 +/- 20.56 g/kg per day (P < 0.01). There were no significant differences in the rates of increase in length and occipitofrontal head circumference between the groups. The lipid content of the hindmilk was 1.6-fold that of composite milk. CONCLUSION: Preterm very low-birthweight babies fed hindmilk had a higher rate of weight gain compared to those fed composite milk. It is recommended that the hindmilk fraction of expressed breast milk be predominantly used for the feeding of preterm very low-birthweight babies while in hospital to help shorten their duration of hospital stay.     

Adequacy of expressed breast milk for early gwoth of preterm infants.

Poor weight gain observed in preterm infants who were fed expressed breast milk compared with those fed a cows'' milk formular prompted a detailed study of early postnatal growth in preterm infants fed these two milks. 68 infants were divided into two categories by gestational age at birth (i) 28-32 weeks (n=28), (ii) 33-36 weeks (n=40). They were randomly allocated to a feed of expressed breast milk or a milk formula (Ostermilk 1). Rates of weight gain, linear growth, and head circumference growth were evaluated over two periods: birth-1 month, 1-2 months. The younger group who were fed breast milk showed slower overall growth rates over the first month than those fed formula. In the second month, and for the older infants over both of the 2-monthly periods, growth rates were similar in the two feeding regimens. It is concluded that expressed breast milk is inadequate for the growth of very immature preterm infants during early postnatal life.     

Application of indirect calorimetry in monitoring feeding of low birth-weight preterm infants

BACKGROUND: We investigated the practical use of indirect calorimetry for the individual nutritional support of preterm infants in order to answer the question whether it is possible to reliably calculate energy expenditure, fat and carbohydrate oxidation in preterm infants individually by using the results of a timed 6-hour-measurement of oxygen consumption and carbon dioxide production. PATIENTS: Measurements were performed in 20 preterm infants (gestational age 30.2 +/- 0.6 weeks, birth weight 1.09 +/- 0.07; mean +/- SEM) at a mean postnatal age of 25 +/- 4 days and with a body weight of 1.35 +/- 0.06 kg. METHODS: Carbon dioxide production (24 h-VCO2), oxygen consumption (24 h-VO2) and respiratory quotient (24 h-RQ) were measured by indirect calorimetry for 24 hours using the Deltatrac II metabolic monitor (Datex, Helsinki, Finland). Additionally, 6 h-VCO2, 6 h-VO2 and 6 h-RQ were determined by measurement over 6 hours. The patients' energy expenditure, fat and carbohydrate oxidation were calculated from VCO2 and VO2 measured over a 24 hour- and 6 hour-period with or without consideration of urinary nitrogen excretion (NU). RESULTS: If NU was not included in the calculation of energy expenditure, the values differed by maximally 1.1% from the calculations including NU. The correlations between the 24 h-RQ and the calculated 24 h-fat or 24 h-carbohydrate oxidation values were statistically significant (r = -0.99; p = 0.0001 and r = 0.773; p = 0.0002 respectively). However, in individual patients, it was not possible to predict 24 h energy expenditure, fat and carbohydrate oxidation of preterm infants using values determined by 6 h indirect calorimetry. CONCLUSION: The determination of the urine-nitrogen excretion is not necessary for calculation of energy expenditure of preterm infants. It is possible to estimate fat and carbohydrate oxidation of preterm infants by the measured 24 h-RQ, but 6 h indirect calorimetry is not accurate enough for calculating the individual nutritional needs of preterm infants in clinical practice. Indirect calorimetry over 24 h may be helpful in the management of selected patients with nutritional problems.     

Supplementation of a bovine milk formula with an oligosaccharide mixture increases counts of faecal bifidobacteria in preterm infants

BACKGROUND: The establishment of a balanced intestinal microflora which may protect against infection is desirable for the preterm infant. OBJECTIVE: To investigate the effect of a preterm formula milk supplement consisting of oligosaccharides in similar proportions to human milk on the faecal flora and stool characteristics of preterm infants. STUDY DESIGN: To resemble the effect of human milk, an oligosaccharide mixture consisting of 90% galacto-oligosaccharides and 10% fructo-oligosaccharides was used to supplement a standard preterm formula at a concentration of 10 g/l. This supplemented formula was studied in 15 preterm infants, and the results were compared with those found in 15 infants fed a formula supplemented with maltodextrin as placebo. A group fed fortified mother's milk was investigated as a reference group (n = 12). On four days during a 28 day feeding period (1, 7, 14, and 28), the faecal flora was investigated, and stool characteristics, growth, and possible side effects were recorded. RESULTS: During the study period, the number of bifidobacteria in the group fed the oligosaccharide supplemented formula increased to the upper range of bifidobacteria counts in the reference group. The difference between the supplemented and non-supplemented groups was highly significant (p = 0.0008). The stool characteristics were also influenced by the supplement: the stool frequency after 28 days was significantly lower in the control group than in the oligosaccharide supplemented group (p = 0.0079) and the reference group (p < 0.0001). Over the study period, the stool consistency in the control group became harder, but remained fairly stable in the other two groups. There was no effect of the different diets on the incidence of side effects (crying, regurgitation, vomiting) or on weight gain or length gain. CONCLUSION: Supplementing preterm formula with a mixture of galacto- and fructo-oligosaccharides at a concentration of 10 g/l stimulates the growth of bifidobacteria in the intestine and results in stool characteristics similar to those found in preterm infants fed human milk. Therefore prebiotic mixtures such as the one studied may help to improve intestinal tolerance to enteral feeding in preterm infants.