The fatty acid composition of banked human milk and infant formulas: The choices of milk for feeding preterm infants

The fatty acid composition of 48 samples of banked human milk for preterm infants and four standard infants formulas available in Finland were analysed by capillary gas liquid chromatography. The banked milk was collected from mothers who had given birth 0–8 weeks previously. Saturated fatty acids accounted for approximately 50% of the fatty acids in both human milk and the formulas, while the relative content of monoenoic fatty acids tended to be higher in human milk than in the formulas. The relative content of 182n–6 was higher in the formulas (range 14.7%–23.2%) than in human milk (median 9.1%, range 6.3%–13.4%). Fat of banked human milk contained 0.9% and 0.7% polyunsaturated fatty acids with 20 and 22 carbon atoms (LCP), respectively, which is comparable to that of fresh mature human milk. In contrast, LCP could not be detected in any of the formulas. Conclusion: Banked human milk is a good source of LCP and offers a good alternative to LCP containing formulas.     

Red blood cell fatty acid composition in low-birth-weight infants fed either human milk or formula during the first months of life

The fatty acid composition of red blood cell (RBC) phospholipids in low-birth-weight infants was determined immediately after delivery and during the first 3 months of life. In the first study, infants were fed either human milk or two formulas with different fatty acid compositions but no long chain polyunsaturated fatty acids (LCPUFA). Both groups of formula-fed infants had significantly lower levels of docosahexaenoic acid (DHA) in RBC phospholipids compared with breast-fed infants. RBC phospholipid DHA was similar in the two formula groups at all ages. In the second study, infants received either a non-supplemented or a LCPUFA-supplemented formula. DHA remained stable in RBC phospholipids of infants supplemented with LCPUFA, whereas DHA decreased in RBC phospholipids of unsupplemented infants. These results confirm that adding DHA to formulas is more effective than increasing 18:3 n-3 content, in maintaining RBC phospholipid DHA levels.     

Fatty acid composition in breast milk and serum phospholipids of healthy term Chinese infants during first 6 weeks of life

AIM: To compare the fatty acid (FA) pattern in early and mature breast milk with that in plasma phospholipids of cord blood and breast-fed infants. METHODS: Forty-five mother-infant pairs from western Shanghai were studied. All infants, born at term with normal weight and length, were examined at birth and days 5 and 42. FA was analyzed by capillary gas-liquid chromatography. RESULTS: Cord blood showed higher concentration of long-chain polyunsaturated FA (LCPUFA) but lower saturated (SFA) and monounsaturated (MUFA) FA than postnatal infants' plasma. SFA decreased with age in the infants, but MUFA and linoleic acid (LA, 18:2omega6) increased. LCPUFA were lower in the plasma of 5-day-old infants than in cord blood, but LA was 80%, alpha-linolenic acid (ALA, 18:3omega3) 33% and the ratio omega-6/omega-3 42% higher. At day 42, LA increased further, LCPUFA remained similar, and was in breast milk lower than at day 5, while ALA and gamma-linolenic acid (18:3omega6) were higher. The activity index of desaturases indicated high Delta9 activity in breast milk and high activity of Delta5 desaturase in the infants. CONCLUSION: Breast milk FA composition changed markedly from day 5 to 42 with increasing correlation to infants' plasma. Calculation of desaturase activities suggested high capacity of LCPUFA synthesis.     

Effects of parenteral soybean oil lipid emulsion on the long-chain polyunsaturated fatty acid profile in very-low-birth-weight infants

Aim: Conventional soybean lipid emulsions contain no docosahexaenoic acid (DHA) or arachidonic acid (AA). We investigated the relationship between blood DHA and AA status in 27 very‐low‐birth‐weight (VLBW) infants with or without parenteral lipid emulsion. Methods: Sixteen infants received parenteral lipid emulsion, and 11 infants were control group. The fatty acid composition of the erythrocyte membrane was analysed at birth and at 2 weeks of age. Results: No significant difference in AA levels was observed in the lipid emulsion group between the two time points, whereas the AA levels at 2 weeks were significantly lower than at birth in the control group. The DHA levels in both groups at 2 weeks were significantly lower than at birth, but no group differences were observed at both time points. Conclusion: The use of parenteral soybean oil lipid emulsions in VLBW infants in the postnatal period may prevent the decline in the AA level but does not appear to influence the DHA level.     

危重症患儿血清脂肪酸构成的临床研究

目的 探讨危重症患儿血清游离脂肪酸构成及含量的变化.方法 采用气相色谱法测定27例危重症患儿和34例健康儿的血清游离脂肪酸谱,比较健康儿、危重症患儿恢复前后的血清游离脂肪酸谱的改变.结果 危重症阶段,血清中棕榈酸、棕榈油酸、油酸、山嵛酸、花生四烯酸及二十碳五烯酸的含量较健康者明显增高(P＜0.05);危重症抢救成功者恢复两周后,血清中豆蔻酸、棕榈酸、棕榈油酸、油酸、花生酸的含量较健康者明显增高(P＜0.05).结论 危重症阶段及危重症抢救成功者恢复后,患儿血清游离脂肪酸谱有变化;危重症的严重应激状态影响血清游离脂肪酸的构成及含量.     

Randomized, double-blind trial of long-chain polyunsaturated fatty acid supplementation with fish oil and borage oil in preterm infants

OBJECTIVE: To test the efficacy and safety of long-chain polyunsaturated fatty acid (LCPUFA) supplementation with gamma-linolenic acid, a precursor of arachidonic acid, and docosahexaenoic acid in preterm infants. STUDY DESIGN: Preterm (<35 weeks, < or =2000 g birth weight) infants (n=238) randomly assigned to unsupplemented or LCPUFA-supplemented formula to 9 months after term. The main outcome measure was the Bayley Mental and Psychomotor Indexes (MDI, PDI) at 18 months after term. Safety outcome measures were anthropometry (9 and 18 months), feed tolerance, infection, and clinical complications. RESULTS: There were no significant differences in neurodevelopment between groups overall. In preplanned subgroup analyses, LCPUFA-supplemented boys had significantly higher Bayley MDI than did control boys (difference, 5.7 points; 95% CI, 0.3 to 11.1; P=.04). LCPUFA-supplemented infants showed significantly greater weight gain (difference, 310 g; 95% CI, 30 to 590 g; P=.03) and length gain (difference, 1.0 cm; 95% CI, 0.02 to 1.9; P=.05) between birth and 9 months, with greater effect in boys (weight difference at 9 months, 510 g; 95% CI, 80 to 930 g; P=.02; length difference at 18 months, 1.8 cm; 95% CI, 0.1 to 1.8; P=.03). CONCLUSIONS: This trial, using the strategy of providing gamma-linolenic acid as a source of arachidonic acid, showed efficacy for growth and for neurodevelopment in boys, with no adverse effects. These data have important implications for LCPUFA-supplementation strategy in preterm infants.     

Fatty acid balance studies in term infants fed formula milk containing long-chain polyunsaturated fatty acids

Long-chain polyunsaturated fatty acids (LCP) are thought to be required for optimal nervous system development in the newborn. A commercial milk formula containing LCP (Aptamil-LCP) with a fatty acid profile closely resembling breast milk, has recently been introduced for term infants. The absorption of fatty acids in term infants was examined in a double-blind randomized controlled trial comparing Aptamil-LCP ( n = 20) and standard Aptamil ( n = 20). Formula-fed newborn infants were studied from birth for 14 d. Fat balances (3 d) were performed from d 10. A 3-d stool collection was performed from d 10 in a parallel breastfed group ( n = 21). Plasma samples were taken on d 6. Median fat excretion (mg kg⁻¹) was 897.1, 615.0 and 355.2 with Aptamil, Aptamil-LCP and breastfeeding, respectively. The median total fat absorption coefficient in Aptamil-LCP-fed infants was higher than in those fed standard Aptamil ( p < 0:01). These findings were accounted for by differences in the excretion and absorption of long-chain saturated fatty acids (C14:0, C16:0 and C18:0). Higher fat excretion was associated with bulkier and firmer stools. Only trace amounts of LCP were detected in the stools of all groups. This accounted for less than 4% of dietary intake in Aptamil-LCP-fed infants. No differences in the utilization of LCP from Aptamil-LCP and breast milk feeding were apparent. Plasma phospholipid fatty acid composition data reflected differences in dietary LCP intake. Thus, PL LCP levels were highest in the breastfed infants and lowest in the Aptamil-fed infants, with values for the Aptamil-LCP-fed group falling in between.     

Serum total and free tryptophan levels in term infants fed cow's milk formula or human milk

We found no significant differences in mean total and free tryptophan concentrations in sera of healthy, full-term infants fed cow's milk formula and healthy, full-term infants who were breast-fed. Serum tryptophan concentrations were measured 1 h after feeding when the infants were 2 and 6 days of age. In this study cow's milk formula compared favourably with human milk as primary nutrition for full-term infants, despite a two-to-three fold higher level of free tryptophan in human colostrum.     

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.     

Plasma amino acid differences in very low birth weight infants fed either human milk or whey-dominant cow milk formula

Midmorning plasma amino acid levels were measured in 31 healthy, very low birth weight infants (mean age 16 days, mean birth weight 1180 g, gestation 29 wk) during 96-h balance studies. All infants received continuous enteral infusion of isonitrogenous, isocaloric preparations of either human milk fortified with pasteurized, lyophilized fractions of mature human milk (n = 18) or whey-dominant cow milk-based formula (n = 13). Weight gain (15 g/kg/day), nitrogen retention (303 mg/kg/day), and metabolizable energy (104 kcal/kg/day) were similar between groups. Plasma levels of threonine, valine, and the sum of essential amino acids were significantly greater in the whey-dominant formula-fed infants (p less than 0.01). Taurine and cystine were measured in significantly greater concentrations in the fortified human milk and threonine, valine, methionine, and lysine in the whey-dominant cow milk formula (p less than 0.01). Relationships between plasma amino acid levels and indices of nitrogen utilization differed between groups. These differences suggest that further modifications of whey-dominant formulas may be indicated.     

Nitrogen and fat balances in very low birth weight infants fed human milk fortified with human milk or bovine milk protein

The study was designed to compare two different human milk fortifiers in a group of very low birth weight (VLBW) infants by analysing nitrogen and fat balances, serum concentrations of alpha-amino-nitrogen, urea, and prealbumin as well as growth rates when human milk enriched with one of the two studied fortifiers was fed to the infants. Fortifier A contained different bovine proteins, peptides and amino acids and had an amino acid composition comparable to that of the nutritional available proteins in human milk, with carbohydrates, and minerals. Fortifier B was composed of freeze-dried skimmed human milk and minerals to achieve a similar macronutrient composition in both fortifiers.Eleven infants were fed with human milk enriched with fortifier A and 13 with fortifier B. After a 10-day equilibration period, a 3-day metabolic balance was performed. On the 14th day of the study blood was obtained preprandially for serum analysis and growth rates were estimated. The nitrogen absorption rate (93.8% vs 93.5%) as well as the retention rate (80.8% vs 78.5%) were no different between the groups. The fat absorption rate (92.3% vs 91.5%) as well as the weight gain (32.1 vs 31.1 g/day) were similar and there were no differences in the serum parameters studied. The results indicate that feeding VLBW infants with human milk enriched with a well-balanced bovine fortifier fulfil their nutritional requirements as well as diets composed exclusively of human milk protein.     

人乳脂肪酸组分与新生儿母乳性黄疸的相关性分析

目的 探讨人乳中不同脂肪酸组分与新生儿母乳性黄疸（BMJ）的相关性。方法 选取2016年10月至2017年10月入住该院新生儿重症监护室,临床诊断为晚发性母乳性黄疸的足月儿作为BMJ组,同期入住月子会所的无黄疸或无病理性黄疸健康新生儿为对照组,每组30例。分别收集两组新生儿的临床资料（包括性别、出生方式、喂养方式、胎龄、出生体重、胎次、产次及总胆红素峰值）及其母亲乳汁,使用MIRIS母乳分析仪检测人乳脂肪、蛋白质、碳水化合物等宏量营养素含量和热卡,采用气相色谱法分析母乳中不同脂肪酸组分含量。结果 对照组人乳各种宏量营养素组分均高于BMJ组,其中脂肪、干物质和热卡差异有统计学意义（P<0.05）。另测得母乳脂肪酸共25种,其中饱和脂肪酸9种,单不饱和脂肪酸6种,多不饱和脂肪酸10种。比较两组不同脂肪酸百分含量发现,BMJ组人乳中C15：0、C16：0、C17：0、C18：0、C20：0、C18：1n9t、C20：1n9、C18：3n6、C22：2、C22：6n3（DHA）等10种长链脂肪酸百分含量均低于对照组,3种脂肪酸C10：0、C12：0、C14：0百分含量均高于对照组（P<0.05）。结论 部分人乳宏量营养素及脂肪酸组分可能与新生儿母乳性黄疸发生机制有关。     

Growth and plasma amino acid concentrations in very low birthweight infants fed either human milk protein fortified human milk or a whey-predominant formula

In a prospective, study involving 20 VLBW-infants (AGA), divided into two study groups of 10 infants, we have evaluated the effects on growth and metabolism of human milk fortified with ultrafiltrated human milk protein and a whey-predominant (whey/casein = 60/40) formula containing 2 g/dl of protein. The study was initiated at a mean age of 30 days when an oral intake of 180 ml/kg/d was tolerated and continued until a weight of 2 kg was reached. The protein intake in both groups was about 3.7 g/kg/d. All infants in both groups reached intrauterine rates of growth for the age, weight gain 18.0 g/kg/d, and length 1.2 cm/week. BUN, acid-base status, total protein and albumin were normal and similar in the two groups. Plasma levels of threonine, glycine, citrulline and methionine were significantly greater in the formula-fed infants. Taurine and proline had higher concentrations in the protein fortified human milk group. There was good tolerance of protein from both sources but the differences in plasma amino acid profiles suggest that the dietary protein quality in formulas for preterm infants must be further modified, if the goal of formula feeding is to achieve metabolic indices of protein metabolism similar to those found when human milk protein is used.     

Fecal cholesterol excretion in preterm infants fed breast milk or formula with different cholesterol contents

In 44 very low-birth-weight infants, fecal cholesterol excretion was measured and in 29 other infants serum total cholesterol concentrations in response to different cholesterol intakes were studied. The infants received fortified breast milk (mean cholesterol content 15.3mg/dl) or were fed either a standard preterm formula (cholesterol content 5.5mg/dl) or the same formula but with a modified lipid composition (long chain polyunsaturated fatty acid concentration closely related to breast milk fat) and 30 mg of cholesterol/dl. In the group fed the high cholesterol formula, fecal cholesterol excretion was significantly higher (35.5mmol/kg/day) than in the groups fed breast milk or the standard formula (20.1 and 18.2mmol/kg/day). Cholesterol balance in the group fed the high cholesterol formula (21.8mg/kg/day) was significantly higher than in the group fed breast milk (+8.6mg/kg/day). In the infants fed the low cholesterol formula the balance was negative (-7.7 mg/ kg/day). Serum concentrations of total cholesterol were similar in the groups fed breast milk or the high cholesterol formula (3.47 and 3.51 mmol/1), but significantly higher than in the group fed the low cholesterol formula (3.15 mmol/1). The data suggest that preterm infants are able to regulate a higher cholesterol intake than during breast feeding by increasing fecal cholesterol excretion as well as decreasing endogenous synthesis.     

Feeding preterm infants a formula containing C20 and C22 fatty acids simulates plasma phospholipid fatty acid composition of infants fed human milk.

Thirty-four premature infants weighing less than 1500 grams at birth were fed preterm formula (formula), preterm infant formula manufactured to contain a balance of C20 and C22 omega 6 and omega 3 fatty acids within the range characteristic of human milk (LCPE-formula) or their mothers' expressed breast milk (EBM). Blood samples were obtained during the first week of life and after 28 days of feeding to determine the effect of feeding C20 and C22 omega 6 and omega 3 fatty acids on plasma lipids. Fatty acid analyses of red blood cell phospholipids indicated few differences between dietary treatment and age. Fatty acid content of plasma cholesterol esters indicated a high plasma cholesterol linoleate level for infants fed formula and a reduced content of C20 and C22 omega 6 and omega 3 fatty acids. For infants fed the modified formula (LCPE-formula) the levels of 20:4 omega 6, 20:5 omega 3 and 22:6 omega 3 were higher than observed for the formula group and similar to those observed for infants fed EBM. By the fifth week of life, feeding the modified formula resulted in plasma phospholipid levels of C20 and C22 omega 6 and omega 3 fatty acids similar to levels of C20 and C22 omega 6 and omega 3 fatty acids found in infants fed EBM and significantly higher than levels characteristic of infants fed formula. It is concluded that infants fed LCPE-formula illustrate an overall balance between C20 and C22 omega 6 to omega 3 fatty acids in the plasma similar to that characteristic of infants fed human milk.     

Long‐chain polyunsaturated fatty acids decline rapidly in milk from mothers delivering extremely preterm indicating the need for supplementation

Aim

Our aim was to perform an in‐depth analysis of the composition of fatty acids in milk from mothers delivering extremely preterm babies. We investigated longitudinal changes in milk fatty acid profiles and the relationship between several types of fatty acids, including omega‐3 and omega‐6.

Methods

Milk samples were collected at three stages of lactation from 78 mothers who delivered at less than 28 weeks of pregnancy at the Sahlgrenska University Hospital, Gothenburg, Sweden, from April 2013 to September 2015. Fatty acid composition was analysed by gas chromatography–mass spectrometry.

Results

A reduction in long‐chain polyunsaturated fatty acids (LCPUFAs) was observed during the lactation period. The concentrations of arachidonic acid and docosahexaenoic acid declined from medians of 0.34 to 0.22 mol% and 0.29 to 0.15 mol%, respectively, between postnatal day 7 and a postmenstrual age of 40 weeks. Strong correlations were found between the intermediates of several classes of fatty acids, including omega‐3, omega‐6 and omega‐9.

Conclusion

A rapid reduction in LCPUFA content in the mother's milk during the lactation period emphasises the importance of fatty acid supplementation to infants born extremely preterm, at least during the period corresponding to the third trimester, when rapid development of the brain and adipose tissue requires high levels of LCPUFAs.     

Plasma amino acid and protein concentrations in infants fed human milk or a whey protein hydrolysate formula during the first month of life

The aim of the study was to compare growth parameters, biochemical indices of protein metabolism and plasma amino acid concentrations in infants fed either human milk ( n = 12) or a whey protein hydrolysate formula ( n = 13) during the first month of life. Growth and gain in skin fold thickness were similar in both groups whereas serum protein concentration was significantly decreased (57.4 ± 3.9 versus 61.2 ± 2.9 g/l) in the infants fed the whey hydrolysate formula. The discrepancies between the plasma amino acid pattern of the whey hydrolysate formula group and that of the human milk group lessened during the first month. Nevertheless, at a mean age of 33 days the plasma threonine concentration remained twice as high and the plasma tyrosine, phenylalanine and proline concentrations were Significantly lower in the whey hydrolysate formula group than in the human milk group. Thus, compared with breast-fed infants, growth and most of the biological indices of protein metabolism were satisfactory in infants fed during the first month of life on a whey protein hydrolysate formula. Nevertheless, the decrease in total plasma protein concentration needs to be confirmed in a larger cohort of infants. In addition, further research is necessary to investigate the possible ways of reducing the hyperthreoninemia and preventing other plasma amino acid disturbances since it would be desirable to obtain plasma amino acid levels similar to those of breast-fed infants.