Vitamin B6- and protein concentrations in breast milk from mothers of preterm and term infants

The vitamin B6 and protein composition of milk obtained during the first 75 days postpartum from 16 mothers delivering preterm and 24 mothers delivering at term was determined. Both groups of mothers had supplemental intake of 5 mg vitamin B6 beginning with the 2nd trimester of gestation but not during lactation. Milk from mothers delivering preterm contained significantly higher concentrations of vitamin B6 and protein than milk from mothers delivering at term. Vitamin B6-protein relationship, however, was significantly lower in milk from mothers delivering preterm than in milk from mothers delivering term. Both, concentrations of vitamin B6 and protein, and vitamin B6-protein ratio decreased with increasing time of lactation. Supplemental vitamin B6 intake during pregnancy is made responsible for this phenomenon. Milk of mothers with preterm infants is adequate to meet the maintainance requirements for vitamin B6 and protein for a premature infant.     

Transmission of cytomegalovirus from mothers to preterm infants by breast milk

OBJECTIVES: To assess the risk of transmission of cytomegalovirus (CMV) by breast milk from CMV-seropositive mothers to their breast-fed preterm infants and to evaluate their outcome. PATIENTS AND METHODS: The study population comprised breast-fed preterm infants with a birth weight of <1,500 g and gestational age of <35 weeks. Venous blood samples from the mothers and infants were tested for CMV IgG and IgM antibodies on the 5th and 30th day after birth. Breast milk was obtained for CMV DNA detection by polymerase chain reaction and viral culture on the 5th day and on the 3rd, 6th and 12th week. Urine samples of the babies were collected at the same time for CMV culture. Neurodevelopmental assessment was done at 6 months of age, corrected for preterm birth. RESULTS: Thirty-eight mothers and 42 infants (including 4 sets of twins) were enrolled in the study. A mother-infant pair was excluded because of inadequate breast milk collection. Thirty-six mothers (97.3%) were CMV-seropositive. CMV DNA of breast milk was detected in 35 seropositive mothers. Six infants of 5 mothers were infected (infected group) at a mean of 77 days after birth, and 34 infants of 31 mothers were not (noninfected group). In all the mothers of the infected group, CMV virus could be cultured from the milk whey. The average maternal CMV IgG on day 5 after delivery was higher in the infected than in the noninfected group. Sepsis-like symptoms and hyperbilirubinemia were more frequently noted in the infected infants than in the noninfected, but the difference was not statistically significant. Neurodevelopmental outcome did not significantly differ between the 2 groups. CONCLUSIONS: The risk of CMV infection in breast-fed premature infants was highest when the mothers shed viable virus in their breast milk. These mothers had high CMV IgG, which may help identify those mother-infant pairs at risk. Inactivation of the virus in milk by freezing may be a way of reducing the transmission of this virus via breast milk.     

早产母乳营养成分的分析

目的 探讨早产儿母亲乳汁营养成分的特点及动态变化。方法 收集2012 年11 月至2014 年1月在北京协和医院产科分娩产妇170 人的母乳339 份,用MIRIS 母乳分析仪检测母乳中宏量营养素及能量,比较各组母乳营养成分的差异。结果 （1）早产母乳中蛋白质含量：初乳> 过渡乳> 成熟乳（2.22±0.49 g/dL vs1.83±0.39 g/dL vs 1.40±0.28 g/dL;PPPPP+1~33+6 周组（2.11±0.25 g/dL）和≥ 34 周组（2.22±0.39 g/dL）比较差异有统计学意义（P+1~33+6 周（51±6 kcal/dL vs 58±8 kcal/dL,P+1~33+6 周组和≥ 34 周组（P+1~33+6 周成熟乳蛋白质显著高于≤ 30 周和≥ 34 周组（P结论 （1）早产初乳、过渡乳和成熟乳营养成分差异显著;（2）早产初乳蛋白质显著高于足月初乳,这种差异未能持续到成熟乳阶段;（3）不同孕周早产产妇母乳营养成分亦存在差异,以适应不同胎龄早产儿的营养需要。     

Lipolytic activity in milk from mothers of unjaundiced infants

Lipoprotein lipase activity and free fatty acid concentrations are measured in samples of milk collected from 50 mothers of infants without prolonged neonatal jaundice; in many samples the values are in the same high range as observed in all samples collected from nine mothers of jaundiced infants. These findings are discussed with relevance to the problems of breast-milk jaundice and factors controlling the milk secretion.     

Cytokines in breast milk from allergic and nonallergic mothers

The allergy-preventing effect of breast-feeding remains controversial, possibly because of individual variations in the composition of the breast milk. The aim of this study was to investigate the concentrations of cytokines involved in allergic reactions and IgA antibody production in breast milk from allergic and nonallergic mothers. The cytokine concentrations were determined in colostrum and 1-mo. milk samples from 24 mothers with, and 25 mothers without, atopic symptoms, using commercial ELISA kits. The immunosuppressive cytokine transforming growth factor-beta was predominant and was detectable in all milk samples. IL-6 was detected in the majority of colostral and mature milk samples, whereas the other cytokines were less commonly detected. The concentrations of IL-6, IL-10, and transforming growth factor-beta, which are all involved in IgA synthesis, correlated with each other and with total IgA concentrations in colostrum. The concentrations of IL-4 were higher in colostrum from allergic than nonallergic mothers, and similar trends were seen for IL-5 and IL-13. In conclusion, transforming growth factor-beta and IL-6 were the predominant cytokines in human milk. The correlation between the concentrations of cytokines involved in IgA synthesis, i.e. IL-10, IL-6, and transforming growth factor-beta, may explain the stimulatory effect on IgA production in breast-fed babies. Varying concentrations of IL-4, IL-5, and IL-13 may explain some of the controversy regarding the possible allergy-preventive effect of breast-feeding.     

Nicotine and cotinine concentrations in serum and urine of infants exposed via passive smoking or milk from smoking mothers

The exposure of infants to nicotine via milk of smoking mothers or via inhaled side-stream smoke ("passive smoking") was evaluated. Newborn infants nursed by smoking mothers and unexposed to passive smoking showed measurable serum concentrations of nicotine (0.2 to 1.6 ng/ml) and its main metabolite, cotinine (5 to 30 ng/ml), and also excreted measurable amounts of nicotine and cotinine in their urine: the ratio of nanograms of nicotine/milligrams of creatinine (N/C ratio) ranged from 5.0 to 110 (median 14), and the corresponding ratio of nanograms of cotinine/milligrams of creatinine (C/C ratio) from 10 to 555 (median 110). Infants of the same age nursed by nonsmoking mothers did not excrete measurable amounts of the two substances except in one case. Older and non-breast-fed infants exposed only to passive smoking had N/C ratios in the range of 4.7 to 218 (median 35) and C/C ratios in the range of 117 to 780 (median 327 ng/mg). Infants exposed to passive smoking and to smoke via breast milk had N/C ratios in the range of 3.0 to 42 (median 12) and C/C ratios in the range of 225 to 870 (median 550). The significant serum concentrations and urinary excretion rates of nicotine in the breast-fed infants of smoking mothers suggest that nursing contributes to the nicotine exposure of these neonates. In older infants, the wide variation of cotinine excretion values did not allow separate evaluation of the two exposure routes.     

Chemoattractant factors in breast milk from allergic and nonallergic mothers

The allergy-preventing effect of breast-feeding remains controversial, possibly because of individual variations in the composition of the breast milk. Recently, we showed that allergic mothers had higher concentrations of IL-4 and lower concentrations of ovalbumin-specific IgA in their breast milk than nonallergic mothers. The aim of this study was to investigate the concentrations of chemokines and cytokines that are chemotactic to cells involved in allergic reactions in breast milk from allergic and nonallergic mothers. Cytokine and chemokine concentrations were determined with ELISA in colostrum and mature milk samples from 23 mothers with and 25 mothers without atopic symptoms. IL-8 was detected in all milk samples. RANTES (regulated on activation, normal T cell expressed and secreted), eotaxin, and IL-16 were detected in 50%, 76%, and 48%, respectively, in colostrum and less commonly in mature milk. Macrophage inflammatory protein-1alpha, however, could not be detected in any of the samples. The concentrations of IL-8 and RANTES were higher in breast milk from allergic, compared with nonallergic, mothers. In conclusion, the presence of chemoattractant factors in breast milk may be responsible for the traffic of leukocytes from the maternal circulation to the breast milk. The higher concentrations of RANTES and IL-8 in allergic mothers may partly explain the controversy regarding the protective effect of breast-feeding against the development of allergy by stronger chemotaxis and activation of cells involved in allergic diseases, and possibly by elevated IgE production.     

Vitamin E in human milk from mothers of preterm and term infants

The content of vitamin E (alpha- and beta + gamma-tocopherol) was analyzed in 63 human milk samples obtained from 13 mothers of preterm infants ("preterm" milk) and in 59 milk samples obtained from nine mothers of full-term infants ("term" milk). The changing pattern of the alpha- and beta + gamma-tocopherol content during the course of lactation was identical for both groups. Total vitamin E, alpha- as well as beta + gamma-tocopherol, decreased during the first 2 weeks of lactation and remained constant thereafter. The ratio of alpha- to beta + gamma-tocopherol decreased from about 10:1 to 4:1. At days 3 and 36 of lactation, vitamin E contents (median values and ranges) expressed as milligrams alpha-tocopherol equivalent per 100 ml were 1.45 (0.64-6.4) and 0.29 (0.17-0.48), respectively, for preterm and 1.14 (0.63-4.21) and 0.28 (0.19-0.86), respectively, for term human milk. The vitamin E, alpha-tocopherol and beta + gamma-tocopherol content of preterm human milk did not differ significantly (p less than or equal to 0.05) from that of term human milk at each sampling day. Based on these findings we conclude that the increased requirement of prematures for vitamin E is not reflected in the vitamin E content of milk from mothers delivering preterm infants.     

Trans fatty acids from milk of Brazilian mothers of premature infants

Aim:   The presence of trans fatty acids (TFA) in human milk may be a concern because of their possible adverse nutritional effects on the infant development. TFA may interfere with the metabolism of long-chain polyunsaturated fatty acids (LC-PUFA). Marked variation in TFA of milk appears in different populations. No data have yet been reported in Brazil, particularly as regards the milk of mothers of premature infants. Because of the importance of LC-PUFA in infant growth and development, we investigated the fatty acids composition of the milk of Brazilian mothers of premature infants.
Methods:   We analysed, through gas-liquid chromatography, the content of fatty acids of 37 milk samples obtained from mothers delivering prematurely. Samples were collected from colostrum and mature milk of exclusive breastfeeding.
Results:   All samples contained trans isomers of C18:1 acid with trans isomers of PUFA in lower proportion. The percentage of TFA (mean ± SD) in the colostrum was 2.34 ± 0.75, and 2.19 ± 0.47 in the mature milk. For the LC-PUFA these values were 0.97 ± 0.34 in the colostrum and 0.66 ± 0.25 in the mature milk. The contents of total essential fatty acids and PUFA n-6 were inversely correlated with TFA in colostrum and mature milk. We found a positive correlation between levels of arachidonic acid in mature milk and change in the children's height.
Conclusions:   The study showed that the intake of TFA occupies an intermediate position between the values of North America and European countries, reflecting the ongoing transition to industrialised foods in Brazil.     

Adiponectin in breast milk: relation to serum adiponectin concentration in lactating mothers and their infants

Aims: The aims of the study were to determine human breast milk adiponectin concentration and to investigate its relationship with serum adiponectin concentration in lactating mothers and their infants and also to evaluate the relationship between serum adiponectin concentration and anthropometric parameters in nurses and infants. Methods: We enrolled 60 healthy term breastfed (BF) infants and their lactating mothers. Adiponectin was determined by radioimmunoassay test in serum and by enzyme‐linked immunosorbent assay test in human milk (HM). Infants’ and mothers’ anthropometric parameters were measured. Results: Median (25‰, 75‰) adiponectin concentration in HM was 9.99 (3.59, 20.52) ng/mL. Serum adiponectin concentration in infants was 60.49 (45.76, 74.24) μg/mL and in lactating mothers 21.14 (12.61, 29.66) μg/mL. Adiponectin concentration in HM correlated positively with adiponectin in mothers’ serum; r = 0.60 (p < 0.001) and in infants’ serum r = 0.37 (p = 0.015). Adiponectin in HM correlated negatively with infants’ age r = ?0.3 (p = 0.04). Infants’ serum adiponectin correlated negatively with their weight r = ?0.35 (p = 0.005), length r = ?0.35 (p = 0.006) and age r = ?0.46 (p < 0.001) and mothers’ serum adiponectin with their weight r = ?0.37 (p = 0.02) and body mass index r = ?0.45 (p = 0.004). Conclusions: The observed correlations between adiponectin in mothers, HM and BF infants may be suggestive for a metabolic link between nurses and infants through milk.     

Serum and saliva Ig-levels in infants of non-atopic mothers fed breast milk or cow's milk-based formulas

Of twenty-five healthy, full term infants without a family history of atopic diseases, 13 were exclusively breast-fed from birth for a minimum of 31/2 months (median 41/2 months), whereas the remaining 12 infants were fed with cow's milk-based formulas from birth for a minimum of 4 months. In the latter group of children a significant increase in serum IgE as well as in salivary IgA was found. In infants exclusively breast-fed, no increase in serum IgE was seen until 6 months of age; at nine months of age, salivary IgA was still significantly lower than in the infants fed cow's milk-based formulas. No children developed obvious allergic diseases during the first three years of life. Thus, cow's milk proteins given to newborn children of non-atopic mothers did not seem to increase the risk of IgE-mediated diseases, maybe due to the development of "blocking" IgA-antibodies in the alimentary tract.     

Concentrations of IL-10 in preterm human milk and in milk from mothers of infants with necrotizing enterocolitis

BACKGROUND: Despite the protective effects of human milk against necrotizing enterocolitis, the incidence is highest in the extremely premature infant, and only minimally decreased with feeding human milk. This suggests that certain protective agents may be lower in milk from mothers delivering extremely premature infants. The anti-inflammatory cytokine IL-10 was one possibility. AIM: We hypothesized that low concentrations of IL-10 in preterm milk contribute to the development of necrotizing enterocolitis in extremely premature infants. METHODS: IL-10 in human milk collected at weeks 1, 2, and 4 postpartum was measured by ELISA in mothers of infants born extremely premature at 23-27 wk gestation (group EP), premature at 32-36 wk gestation (group P), and term at 38-42 wk gestation (group T). Single milk samples were collected from a separate group of mothers whose infants developed necrotizing enterocolitis. RESULTS: There were no significant differences in concentrations of milk IL-10 among groups EP, P, or T. Concentrations of IL-10 declined as lactation progressed (p < 0.001). IL-10 in milk was frequently undetected in all groups, but even more so in the milk of the group of women whose infants had necrotizing enterocolitis (86%) than in groups EP (40%) and P (27%) (p < 0.01). CONCLUSION: IL-10 was present in preterm milk from most women, and the concentrations in preterm and term milk were not significantly different. A paucity of IL-10 in human milk was found in certain mothers in each group, especially in those whose infants developed necrotizing enterocolitis.