Systematic review of fatty acid composition of human milk from mothers of preterm compared to full-term infants

Background: Fatty acid composition of human milk serves as guidance for the composition of infant formulae. The aim of the study was to systematically review data on the fatty acid composition of human milk of mothers of preterm compared to full-term infants. Methods: An electronic literature search was performed in English (Medline and Medscape) and German (SpringerLink) databases and via the Google utility. Fatty acid compositional data for preterm and fullterm human milk were converted to differences between means and 95% confidence intervals. Results: We identified five relevant studies publishing direct comparison of fatty acid composition of preterm versus full-term human milk. There were no significant differences between the values of the principal saturated and monounsaturated fatty acids. In three independent studies covering three different time points of lactation, however, docosahexaenoic acid (DHA) values were significantly higher in milk of mothers of preterm as compared to those of full-term infants, with an extent of difference considered nutritionally relevant. Conclusion: Higher DHA values in preterm than in full-term human milk underlines the importance of using own mother's milk for feeding preterm babies and raises the question whether DHA contents in preterm formulae should be higher than in formulae for full-term infants. Copyright (c) 2008 S. Karger AG, Basel

Les sols des marais maritimes du littoral occidental malgache

L'étude des sols de quelques marais maritimes du littoral occidental de Madagascar met en évidence leur grande diversité et une rapide salinisation menant à la disparition des mangroves et à leur substitution par des tanne

Sur un double mécanisme d'acidification des sols sous l'influence de cendres volcaniques récentes : le cas de la Soufrière de Guadeloupe après les éruptions de 1976-1977

L'acidification rapide et durable d'andosols recouverts par les cendres de la Soufrière de Guadeloupe (1976-1977) est due à la conjonction originale de deux mécanismes inhérents à la composition de dépôts : acidité aluminique immédiate provenant de smectites à aluminium interfoliaire, acidification progressive due à l'oxydation de pyrites. (Résumé d'auteur

Placental regulation of fetal nutrient supply

Purpose of review Placental nutrient uptake and transfer may have a unique role, as changes in trophoblast nutrient-sensing signaling pathways regulate cell metabolism and may affect the fetal growth and health programming in the offspring. Recent findings The functionality of the placenta could affect the neonatal adiposity and the fetal levels of key nutrients such as long-chain polyunsaturated fatty acids. Insulin, oxygen and amino acid concentrations may regulate the mammalian target of rapamycin (mTOR) nutrient sensor in the human placenta affecting trophoblast metabolism and nutrient delivery. Summary The mechanisms involved in both placental uptake and transfer of macronutrients are reviewed. Fatty acid, cholesterol and amino acid transport across the placenta involves a complex system to ensure nutrient delivery to the growing fetus. The placental glucose transfer is important for fetal macrosomia, but lipid disturbances in both maternal and placental compartments may contribute to neonatal fat accretion. Maternal insulin has little effect on the avidity of glucose transport by the placenta, but may interfere in placental metabolism via mTOR nutrient sensor. mTOR is a positive regulator of the amino acid carriers and constitutes a critical link between maternal nutrient availability and fetal growth, thereby influencing the long-term health of the fetus

Omega 3 fatty acids, gestation and pregnancy outcomes

Pregnancy is associated with a reduction in maternal serum docosahexaenoic acid (DHA, 22:6 n-3) percentage and its possible depletion in the maternal store. Since the synthesis of long chain polyunsaturated fatty acids (LCPUFA) in the fetus and placenta is low, both the maternal LCPUFA status and placental function are critical for their supply to the fetus. Maternal supplementation with DHA up to 1 g/d or 2·7 g n-3 LCPUFA did not have any harmful effect. DHA supplementation in large studies slightly the enhanced length of gestation (by about 2 days), which may increase the birth weight by about 50 g at delivery. However no advice can be given on their general using to avoid preterm deliveries in low or high risk pregnancies. Several studies, but not all, reported improvements of the offspring in some neurodevelopmental tests as a result of DHA supplementation during gestation, or, at least, positive relationships between maternal or cord serum DHA percentages and cognitive skills in young children. The effect seems more evident in children with low DHA proportions, which raises the question of how to identify those mothers who might have a poor DHA status and who could benefit from such supplementation. Most studies on the effects of n-3 LCPUFA supplementation during pregnancy on maternal depression were judged to be of low-to-moderate quality, mainly due to small sample sizes and failure to adhere to Consolidated Standards of Reporting Trials guidelines. In contrast, the effects of n-3 LCPUFA supplementation on reducing allergic diseases in offspring are promising.</jats:p