Allergen Shedding in Human Milk from Mothers of Preterm Infants: Proteomic and Peptidomic Feasibility and Pilot Analysis

Rationale: There is little information regarding the allergen content of milk feeds in the preterm population. Previous studies have evaluated specific proteins/peptides via ELISA, but no studies have performed a broad analysis of the allergenic peptide content and protease activity of milk feeds in this population. Preterm infants spend a critical window of time for immune development in the Newborn Intensive Care Unit (NICU), and may receive fortified donor milk, maternal milk or formula feeds via nasogastric tube or bottle instead of fresh breastmilk via breastfeeding. Methods: To evaluate feasibility, we initially performed mass spectrometry on four human milk samples (two term and two preterm) from the Mommy’s Milk Human Milk Biorepository (HMB) which included maternal surveys of diet and environmental exposures. We analyzed the results against the University of Nebraska FASTA database and UniProt for a total of 2211 protein sequences. We then further analyzed 5 samples from the Microbiome, Atopy and Prematurity (MAP) pilot study along with formula and human milk fortifier controls and performed not only mass spectrometry, but also peptidomic and protease activity analysis. Results: Each HMB sample had between 806 and 1007 proteins, with 37 to 44 non-human proteins/sample encompassing 26 plant and animal species. Bovine proteins were the most numerous; seven unique Bos taurus proteins were found in all four samples, and three contained Bos d 5. Cat, dog, mosquito, salmon, and crab were detected in all four samples. All donors ingested fish, shellfish and tree nuts, and all had salmon and crab proteins in their milk samples; two almond proteins were detected in three samples. Aeroallergens, including dust mite (Der f 28, Der f 25) and mold (Cla h 4) were identified in all samples. Two samples contained allergens to latex (Hev b 9) and chicken (Gal d 10). One sample contained several unique proteins, including carrot, two molds (including Pen c 19) and Der f 33-like protein. In the preterm MAP samples, 784 digested non-human proteins were identified, 30 were non-bovine in origin. Proteins from 23 different species including aeroallergens, food, and contact allergens were identified. Protease activity was highest in human milk samples without human milk fortifier and lowest in preterm formula. Conclusions: These findings represent the first preterm milk feed mass spectrometry and protease analysis with identification of known allergenic proteins to food, contact and aeroallergens. The varying degree of protein detection may reflect variable individual secretion and augmentation of feeds. This raises questions of whether the composition of milk feeds in the NICU impact the development of atopic disease in the preterm population and whether the complex interaction between allergens, proteases, and other human milk components can serve to induce sensitization or tolerance to allergens in infants.

Use of probiotics in the NICU: Evaluating the stability of a three-strain probiotic blend in various media for enteral feeding

BACKGROUND: There is little published data on how to prepare probiotic supplements for enteral delivery in the NICU. The objective of this study was to determine how a three-strain probiotic blend (Bb-02, TH-4 ® and BB-12 ®) would behave when mixed and held for 4 hours with saline water, sterile water, dextrose 5% in water (D5W), 24 kcal preterm formula, and human milk. METHODS: A packet of a three-strain probiotic supplement was mixed with 3 ml of saline water, sterile water, D5W, 24 kcal preterm formula, and human milk (tested at 3 ml and 2 ml). Samples were stored at room temperature for 60 minutes then refrigerated for 180 minutes. Probiotic survival, using quantitative enumeration, and pH were monitored over 4 hours. Samples were passed through a 5 French (Fr) feeding tube at the end of the study to evaluate viscosity. RESULTS: The largest variation in total cell count from 0-time was sterile water with a + 0.26 log(CFU)/mL change at 90 minutes and typical variation is considered±0.50 log units indicating no significant change between samples in 4 hours. Saline water had the lowest final pH at 4.88. All samples easily passed through a 5 Fr feeding tube. CONCLUSION: The study showed minimal change in cell counts across solutions for 4 hours of storage, indicating health care facilities may be able to prepare probiotic supplements with a variety of solutions in pharmacies or milk rooms. This allows greater flexibility for probiotic delivery to preterm infants.

Nordic study on human milk fortification in extremely preterm infants: a randomised controlled trial—the N-forte trial

IntroductionThe mortality rate of extremely low gestational age (ELGA) (born <gestational week 28+0) infants remains high, and severe infections and necrotising enterocolitis (NEC) are common causes of death. Preterm infants receiving human milk have lower incidence of sepsis and NEC than those fed a bovine milk-based preterm formula. Despite this, fully human milk fed ELGA infants most often have a significant intake of cow’s milk protein from bovine-based protein fortifier. The aim of this study is to evaluate whether the supplementation of human milk-based, as compared with bovine-based, nutrient fortifier reduces the prevalence of NEC, sepsis and mortality in ELGA infants exclusively fed with human milk.Methods and analysisA randomised-controlled multicentre trial comparing the effect of a human breast milk-based fortifier with a standard bovine protein-based fortifier in 222–322 ELGA infants fed human breast milk (mother’s own milk and/or donor milk). The infants will be randomised to either fortifier before reaching 100 mL/kg/day in oral feeds. The intervention, stratified by centre, will continue until the target postmenstrual week 34+0. The primary outcome is a composite of NEC, sepsis or death. Infants are characterised with comprehensive clinical and nutritional data collected prospectively from birth until hospital discharge. Stool, urine, blood and breast milk samples are collected for analyses in order to study underlying mechanisms. A follow-up focusing on neurological development and growth will be performed at 2 and 5.5 years of age. Health economic analyses will be made.Ethics and disseminationThe study is conducted according to ICH/GCP guidelines and is approved by the regional ethical review board in Linköping Sweden (Dnr 2018/193-31, Dnr 2018/384-32). Results will be presented at scientific meetings and published in peer-reviewed publications.Trial registration numberThe study was registered with ClinicalTrials.gov NCT03797157, 9 January 2019.

Is preterm donor milk better than preterm formula for very-low-birth-weight infants?

Background: Preterm human milk has advantages over preterm formula (PF), but it may compromise some functions after pasteurization. Objective: To explore the effects of preterm donor milk (DM) on growth, feeding tolerance, and severe morbidity in very-low-birth-weight infants. Method: This was a single-center, prospective cohort study that included 304 preterm infants weighing <1,500 g or of gestational age <32 weeks. If the mother’s own milk was insufficient, the parents decided to use PF (n = 155) or DM (n = 149). The two groups were uniformly managed according to the standard NICU protocol. Growth parameters, feeding tolerance, and severe morbidity such as necrotizing enterocolitis, were compared between the two groups. Results: The daily weight gain and weekly head growth in the DM group were not different from those in the PF group (P > 0.05). Feeding intolerance in the DM group was significantly lower than that in PF group (P < 0.05), and parenteral nutrition time and hospitalization time were also shorter than that in the PF group (P < 0.05). Moreover, the incidence of necrotizing enterocolitis and sepsis was also significantly lower in the DM group (P < 0.05). Conclusion: The study indicated that preterm DM does not affect the growth of very-low-birth-weight infants. Further, it significantly reduces feeding intolerance, helps achieve full enteral feeding early, and has protective effects against necrotizing enterocolitis and sepsis. Thus, compared with formula, preterm DM can lower the rate of infection in preterm infants and is worthy of promotion.

A Systematic Review and Meta-Analysis of Human Milk Feeding and Short-Term Growth in Preterm and Very Low Birth Weight Infants

Human milk (HM) is the gold standard for feeding infants but has been associated with slower growth in preterm infants compared with preterm formula. This systematic review and meta-analysis summarises the post-1990 literature to examine the effect of HM feeding on growth during the neonatal admission of preterm infants with birth weight ≤1500 g and/or born ≤28 weeks’ gestation. Medline, PubMed, CINAHL, and Scopus were searched, and comparisons were grouped as exclusive human milk (EHM) vs. exclusive preterm formula (EPTF), any HM vs. EPTF, and higher vs. lower doses of HM. We selected studies that used fortified HM and compared that with a PTF; studies comparing unfortified HM and term formula were excluded. Experimental and observational studies were pooled separately. The GRADE system was used to evaluate risk of bias and certainty of evidence. Forty-four studies were included with 37 (n = 9963 infants) included in the meta-analyses. In general, due to poor quality studies, evidence of the effect of any HM feeds or higher versus lower doses of HM was inconclusive. There was a possible effect that lower doses of HM compared with higher doses of HM improved weight gain during the hospital admission, and separately, a possible effect of increased head circumference growth in infants fed EPTF vs. any HM. The clinical significance of this is unclear. There was insufficient evidence to determine the effects of an exclusive HM diet on any outcomes.

“Aggressive” Feeding of Very Preterm Neonates and Body Mass Index at School Age

Introduction: The effects of “aggressive” neonatal feeding policies of very preterm neonates (VPN) and the risk of metabolic syndrome later in life remain questionable. We aimed to evaluate the effect of our “aggressive” nutrition policies of VPN during hospitalisation on body mass index (BMI) at ages 2 and 8 years. Materials and Methods: Eighty four VPN, who received “aggressive” nutrition during hospitalisation in an effort to minimise postnatal growth restriction (PGR) (group A), and 62 term neonates, as controls (group B), were enrolled in the study. Group A was further divided in four subgroups depending on the type (A1: fortified expressed breast milk and preterm formula; A2: exclusively preterm formula) and quantity of milk received (A3: maximum feeds 180–210 mL/kg/day; A4: maximum feeds 210 and up to 260 mL/kg/day). BMI was calculated at ages 2 and 8 years and plotted on the centile charts. Results: There was no significant difference in BMI between groups A and B at 2 and 8 years, respectively, in both absolute BMI values and their centile chart distribution. There was no significant difference in BMI at 2 and 8 years either between subgroups A1 and A2 or between subgroups A3 and A4. Conclusions: “Aggressive” and individualised feeding policy for VPN did not affect the BMI and obesity rates at ages of 2 and 8 years in our study population. The type and quantity of milk feeds had no impact on their BMI at school age. Further larger studies are needed to confirm our results.

A Systematic Review and Meta-Analysis of Human Milk Feeding and Short-Term Growth in Preterm and Very Low Birth Weight Infants

Human milk (HM) is the gold standard for feeding infants but has been associated with slower growth in preterm infants compared with preterm formula. This systematic review and meta-analysis summarises the post-1990 literature to examine the effect of HM feeding on growth during the neonatal admission of preterm infants with birth weight &le;1500g and/or born &le;28 weeks&rsquo; gestation. Medline, PubMed, CINAHL and Scopus were searched, and comparisons grouped as: exclusive human milk (EHM) vs exclusive preterm formula (EPTF), any HM vs EPTF and higher vs lower doses of HM. We selected studies that used fortified HM and compared that with a PTF; studies comparing unfortified HM and term formula were excluded. Experimental and observational studies were pooled separately. The GRADE system was used to evaluate risk of bias and certainty of evidence. Forty-four studies were included with 37 (n =9,963 infants) included in the meta-analyses. In general, due to poor quality studies, evidence of the effect of any HM feeds or higher versus lower doses of HM was inconclusive. There was a possible effect that lower doses of HM compared with higher doses of HM improved weight gain during the hospital admission, and separately, a possible effect of increased head circumference growth in infants fed EPTF vs any HM. The clinical significance of this is unclear. There was insufficient evidence to determine the effects of an exclusive HM diet on any outcomes.