The effect of gestational and lactational age on the human milk metabolome

Human milk is the ideal nutrition source for healthy infants during the first six months of life and a detailed characterisation of the composition of milk from mothers that deliver prematurely (<37 weeks gestation), and of how human milk changes during lactation, would benefit our understanding of the nutritional requirements of premature infants. Individual milk samples from mothers delivering prematurely and at term were collected. The human milk metabolome, established by (NMR) spectroscopy, was influenced by gestational and lactation age. Metabolite profiling identified that levels of valine, leucine, betaine, and creatinine were increased in colostrum from term mothers compared with mature milk, while those of glutamate, caprylate, and caprate were increased in mature term milk compared with colostrum. Levels of oligosaccharides, citrate, and creatinine were increased in pre-term colostrum, while those of caprylate, caprate, valine, leucine, glutamate, and pantothenate increased with time postpartum. There were differences between pre-term and full-term milk in the levels of carnitine, caprylate, caprate, pantothenate, urea, lactose, oligosaccharides, citrate, phosphocholine, choline, and formate. These findings suggest that the metabolome of pre-term milk changes within 5-7 weeks postpartum to resemble that of term milk, independent of time of gestation at pre-mature delivery.

Nutrition, growth and body composition in preterm infants

The goal of neonatal nutrition in the preterm infant is to achieve postnatal growth and body composition approximating that of a normal fetus of the same postmenstrual age and to obtain a functional outcome comparable to infants born at term. However, in clinical practice such a pattern is seldom achieved, with growth failure and altered body composition being extensively reported. The BabyGrow preterm nutrition study was a longitudinal, prospective, observational study designed to investigate nutrition and growth in 59 preterm infants following the implementation of evidence-based nutrition guidelines in the neonatal unit at Cork University Maternity Hospital. Nutrient delivery was precisely measured during the entire hospital stay and intakes were compared with current international recommendations. Barriers to nutrient delivery were identified across the phases of nutritional support i.e. exclusive parenteral nutrition and transition (establishment of enteral feeds) phases of nutrition and nutritional strategies to optimise nutrient delivery were proposed according to these phases. Growth was measured from birth up to 2 months corrected age and body composition was assessed in terms of fat mass and lean body mass by air displacement plethysmography (PEA POD) at 34 weeks gestation, term corrected age and 2 months corrected age. Anthropometric and body composition data in the preterm cohort were compared with a term reference group from the Cork BASELINE Birth Cohort Study (n=1070) at similar time intervals. The clinical and nutritional determinants of growth and body composition during the neonatal period were reported for the first time. These data have international relevance, informing authoritative agencies developing evidence-based practice guidelines for neonatal nutritional support. In the future, the nutritional management of preterm infants may need to be individualised to consider gestational age, birth weight as well as preterm morbidity.

Improving the care of preterm infants: before, during, and after, stabilisation in the delivery room

Introduction Up to 10% of infants require stabilisation during transition to extrauterine life. Enhanced monitoring of cardiorespiratory parameters during this time may improve stabilisation outcomes. In addition, technology may facilitate improved preparation for delivery room stabilisation as well as NICU procedures, through educational techniques. Aim To improve infant care 1) before birth via improved training, 2) during stabilisation via enhanced physiological monitoring and improved practice, and 3) after delivery, in the neonatal intensive care unit (NICU), via improved procedural care. Methods A multifaceted approach was utilised including; a combination of questionnaire based surveys, mannequin-based investigations, prospective observational investigations, and a randomised controlled trial involving preterm infants less than 32 weeks in the delivery room. Forms of technology utilised included; different types of mannequins including a CO2 producing mannequin, qualitative end tidal CO2 (EtCO2) detectors, a bespoke quantitative EtCO2 detector, and annotated videos of infant stabilisation as well as NICU procedures Results Manual ventilation improved with the use of EtCO2 detection, and was positively assessed by trainees. Quantitative EtCO2 detection in the delivery room is feasible, EtCO2 increased over the first 4 minutes of life in preterm infants, and EtCO2 was higher in preterm infants who were intubated. Current methods of heart rate assessment were found to be unreliable. Electrocardiography (ECG) application warrants further evaluation. Perfusion index (PI) monitoring utilised in the delivery room was feasible. Video recording technology was utilised in several ways. This technology has many potential benefits, including debriefing and coaching in procedural healthcare, and warrants further evaluation. Parents would welcome the introduction of webcams in the NICU. Conclusions I have evaluated new methods of improving infant care before, during, and after stabilisation in the DR. Specifically, I have developed novel educational tools to facilitate training, and evaluated EtCO2, PI, and ECG during infant stabilisation. I have identified barriers in using webcams in the NICU, to now be addressed prior to webcam implementation.

Effect of room temperature transport vials on DNA quality and phylogenetic composition of faecal microbiota of elderly adults and infants

Background: Alterations in intestinal microbiota have been correlated with a growing number of diseases. Investigating the faecal microbiota is widely used as a non-invasive and ethically simple proxy for intestinal biopsies. There is an urgent need for collection and transport media that would allow faecal sampling at distance from the processing laboratory, obviating the need for same-day DNA extraction recommended by previous studies of freezing and processing methods for stool. We compared the faecal bacterial DNA quality and apparent phylogenetic composition derived using a commercial kit for stool storage and transport (DNA Genotek OMNIgene GUT) with that of freshly extracted samples, 22 from infants and 20 from older adults. Results: Use of the storage vials increased the quality of extracted bacterial DNA by reduction of DNA shearing. When infant and elderly datasets were examined separately, no differences in microbiota composition were observed due to storage. When the two datasets were combined, there was a difference according to a Wilcoxon test in the relative proportions of Faecalibacterium, Sporobacter, Clostridium XVIII, and Clostridium XlVa after 1 week's storage compared to immediately extracted samples. After 2 weeks' storage, Bacteroides abundance was also significantly different, showing an apparent increase from week 1 to week 2. The microbiota composition of infant samples was more affected than that of elderly samples by storage, with significantly higher Spearman distances between paired freshly extracted and stored samples (p