Gut colonization in preterm infants supplemented with bovine colostrum in the first week of life: An explorative pilot study.

BACKGROUND: In the first weeks after birth, enteral feeding and bacterial colonization interact to influence gut maturation in preterm infants. Bovine colostrum (BC) has been suggested as a relevant supplementary diet when own mother's milk (MM) is insufficient or absent. This pilot trial tests whether the supplement type, BC or donor human milk (DM), affects gut colonization in preterm infants during the first week of life. METHODS: On day 7, fecal samples were collected from preterm infants (n = 24) fed BC or DM as a supplement to MM. The gut microbiome (GM) was analyzed by 16S ribosomal RNA amplicon sequencing. Correlations between the relative abundance of specific bacterial taxa and blood chemistry variables, including amino acids, were explored. RESULTS: BC-supplemented infants showed a lower relative abundance of the families Lactobacillaceae and Enterococcaceae than DM infants. Planococcaceae were more abundant in infants delivered by cesarean birth vs vaginally. The relative abundance of bacterial families, specifically Enterobacteriaceae, correlated negatively with plasma levels of multiple essential and nonessential amino acids (valine, isoleucine, lysine, histidine, and arginine). CONCLUSION: The nature of nutrition supplements (BC or DM) just after birth may affect GM development and nutrient metabolism in the neonatal period of preterm infants. The exploratory nature of our study calls for confirmation of these results and their possible long-term clinical implications for preterm infants.

Incidence and risk of necrotizing enterocolitis in Denmark from 1994-2014.

INTRODUCTION: We suspected that the incidence of NEC in Denmark had increased during the last 20 years but hypothesized that this could be explained by the increased neonatal survival. METHODS: We conducted a retrospective, observational cohort study of all registered liveborn infants in Denmark in the period from January 1, 1994 to December 31, 2014. Data were obtained from the Medical Birth Registry, National Patient Register, and Cause of Death register in Denmark. The primary outcome was the registration of NEC (ICD-10: DP77.9) during a hospital admission within 6 months after birth. The statistical analysis used 'death before NEC' as a competing risk. RESULTS: The cohort consisted of 1,351,675 infants, of which 8,059 died. There was a strongly significant decreasing risk of death over the period for the all infants (p<0.0001 in all gestational age groups). In total, 994 infants were diagnosed with NEC which lead to an incidence of 7.4 per 10,000 live-born infants. During the observation period, the incidence increased from 6.3 to 7.9 per 10,000 births (p = 0.006). When accounting for 'death before NEC' as a competing risk, the increase could be explained by the increased neonatal survival. There was, however, a GA-group/epoch interaction (p = 0.008) in the cause-specific hazard ratios with a trend towards an increasing risk of NEC in the most preterm infants and a decreasing risk of NEC in the term infants. CONCLUSION: While the overall incidence of NEC increased over the study period, the overall risk of NEC did not increase when considering the increased survival. Nevertheless, there seemed to be an increased risk of NEC in the most premature infants which was masked by a decreased risk in the term infants. This study suggests that research to prevent NEC in the most preterm infants is more important now than ever.

Behavioural and neurodevelopmental impairment at school age following necrotising enterocolitis in the newborn period.

AIM: The aim of this study was to evaluate long-term behavioural and neurodevelopmental complications of neonatal necrotizing enterocolitis at school age. METHOD: This was a historic cohort study comparing all surviving children born in Denmark between 1st of January 2002 and 31st of December 2011 with a diagnosis of necrotizing enterocolitis to a group of children without necrotizing enterocolitis, but same gestational age, birth weight and year of birth. Outcomes were investigated through a parental questionnaire. The primary outcome was the Strength and Difficulties Questionnaire score and secondary outcomes were cerebral palsy and impaired head growth. RESULTS: Response rates were 50% (163 of 328) and 36% (237 of 652) among children with and without necrotizing enterocolitis, respectively. There was a higher rate of abnormal Strength and Difficulties score (23.9 versus 17.8%), moderate/severe cerebral palsy (3.1 versus 0.9%) and small head circumference for age (11.7 versus 7.2%) among children with necrotizing enterocolitis. However, these differences were all statistically insignificant and did not change significantly by adjustment for potential confounders. CONCLUSION: To our knowledge, this study includes the largest cohort of necrotizing enterocolitis children evaluated for possible long-term complications at school age. The increased risks of behavioural- and neurodevelopmental impairments were statistically insignificant, moderate in magnitude and may be of little clinical importance for management in the neonatal period or when planning follow-up.

Staging of necrotising enterocolitis by Bell's criteria is supported by a statistical pattern analysis of clinical and radiological variables.

AIM: Necrotising enterocolitis (NEC) is often staged according to Bell's 1978 system, but today's NEC cases are more immature than the ones that were used to develop Bell's stages. Our aim was to explore the clinical and radiographic findings of contemporary cases of NEC and spontaneous intestinal perforation. METHODS: We coded the clinical records of all cases of NEC stages I-III and spontaneous intestinal perforation born in 2006-2015 at the tertiary department of neonatology at Rigshospitalet, Denmark, for 16 clinical and radiographic symptoms and signs at disease onset and at climax. These variables were explored using principal component analysis, which can detect patterns in large datasets. RESULTS: We reviewed 640 clinical records and included 158 cases of NEC or spontaneous intestinal perforation. When we entered the clinical and radiographic signs at disease climax, the cases were roughly grouped according to Bell's stages, except for a small group of NEC III cases, who were grouped with the cases of spontaneous intestinal perforation. CONCLUSION: An analysis of the pattern of clinical and radiographic findings in a 2006-2015 population of NEC cases supported Bell's 1978 staging system. However, the separation between NEC and spontaneous intestinal perforation still poses a difficult task.

Bovine Colostrum for Preterm Infants in the First Days of Life: A Randomized Controlled Pilot Trial.

OBJECTIVES: Mother's own milk (MM) is the best nutrition for newborn preterm infants, but is often limited in supply just after birth. Pasteurized human donor milk (DM), and especially preterm infant formula (IF) are less optimal diets than MM. We hypothesized that it is feasible to use bovine colostrum (BC), the first milk from cows, as a supplement to MM, during the first weeks after preterm birth. METHODS: In an open-label, randomized, controlled pilot safety trial, supplementation of MM with BC was compared with DM supplementation (Danish unit) or IF supplementation (Chinese unit). If MM was limited or lacking, BC, DM or IF were given according to local feeding guidelines during the first 14 days of life. RESULTS: Forty infants were included and randomized in Denmark and in China, with gestational ages 29.9 ±â€Š0.4 and 31.1 ±â€Š0.2 weeks, respectively. Infants supplemented with BC received more enteral protein (P < 0.05) and tended to reach full enteral feeding earlier (China only). Eight infants fed BC showed a temporary elevation in plasma tyrosine on day 7, versus 2 infants in the DM/IF groups. There were no differences between diet groups in feeding intolerance or clinical adverse events. CONCLUSIONS: Our results indicate that it is feasible to use BC as a supplement to MM during the first weeks of life to increase enteral protein intake in preterm infants. Plasma tyrosine levels may be a good marker for excessive protein intake. A larger randomized trial is required to test the safety and possible short- and long-term clinical benefits of BC supplementation during the first weeks of life for preterm infants.

Necrotizing enterocolitis - classification and two initial steps towards prevention.

The premature infant suffers from immaturity of all organ systems, one of them being the gastrointestinal tract. When the infant is born, the immature gastrointestinal tract is exposed to milk and simultaneously colonized by high densities of bacteria. The combination of milk, microbiota and an immature gut, leaves the infant vulnerable to developing the dreaded intestinal emergency necrotizing enterocolitis (NEC). NEC is often very aggressive and no cure exists, which means that prevention is an utmost important topic to researchers, physicians, parents - and infants.   Despite immense research during the last decades, no specific test to determine if an infant suffers from NEC exists. Most neonatal units use Bell's staging criteria, which are based on clinical and radiographic findings, as a diagnostic tool; however the diagnosis given according to Bell's stages has not been validated. In study I, we aimed to determine the validity of the NEC diagnosis given at discharge. An expert panel consisting of a neonatologist, a paediatric surgeon and a paediatric radiologist served as the golden standard. We found that the diagnosis given at discharge had a poor validity which significantly affected the reported incidence of NEC in the neonatal department at Rigshospitalet, Denmark. The validity of the NEC diagnosis was worse than the validity of most other paediatric diagnoses that had been investigated.   In studies II and III, we aimed to explore possible means of NEC prevention. The role of nutrition in NEC development is well established with mother's milk as the best option to avoid NEC in the preterm infant. Maternal milk is, however, most often not available in sufficient amounts during the first days of life, and preterm infant formula or human donor milk is used in its absence. Studies in preterm piglets showed that bovine colostrum equally to human donor milk protected against NEC compared to infant formula. Furthermore, bovine colostrum was superior to human donor milk in stimulating gut immunity and digestive functions.   Hence, in study II we aimed to design a pilot study of bovine colostrum used as a supplement to maternal milk in the first days of life and to determine if the study was feasible. In the paper, we present the protocol and the results of the first two phases of the Precolos study in which 12 infants were included and received pasteurized, spray-dried and reconstituted bovine colostrum during the first days of life as the first infants in the world. We found that the infants tolerated bovine colostrum without clinical adverse effects, but we also observed a transient hypertyrosinemia on day seven of life in five infants. The results were evaluated by a safety management board which encouraged us to continue the pilot study with the last phase, which was a randomized controlled trial of 20+20 infants comparing supplementation with bovine colostrum to supplementation with standard nutrition. The randomized trial has just finished recruitment.   At last, we wanted to shed light on a possible microbiological angle of NEC prevention. Dysbiosis and bacterial translocation are believed to play a crucial role in the development of NEC as intestinal pneumatosis, which occurs when bacteria produce gas inside the intestinal wall, is a pathognomonic radiographic finding. In a quality improvement study from the US published in 2014, NEC incidence was significantly reduced after the implementation of several quality improvement interventions. Standardized weekly exchange of nasogastric feeding tubes was suggested as one of the potential NEC-reducing interventions.   In the neonatal unit at Rigshospitalet, Denmark, preterm infants are fed 8-12 times daily through a resident nasogastric feeding tube which is exposed to body temperature, contains milk residuals from the last meal and is handled by both parents and personnel. Since bacterial pollution of milk given through the nasogastric feeding tube might be NEC-inducing, we aimed in study III to determine the bacterial load given to the infants when feeding them through a tube. We collected 92 used nasogastric feeding tubes and flushed them with one ml saline each to imitate a meal given through them. Eighty-nine percent of the tubes contaminated the meals with more than 1000 colony-forming units of bacteria and fifty-five percent contaminated the meals with the possible pathogens Enterobacteriaceae or Staphylococcus aureus. The concentration of bacteria in the saline flushed through the tubes was as high as 109 colony-forming units per ml; however, neither the risk of contamination nor the concentration of bacteria in the flush was associated with the duration of use. Implementation of standardized weekly exchange of feeding tubes would therefore not prevent the contamination of meals.   In conclusion, the studies included in this thesis serve as a base for future studies investigating the prevention of NEC. We found a poor validity of the NEC diagnosis given at discharge. This should be kept in mind when conducting epidemiological studies of NEC and especially when conducting interventional trials with NEC as an outcome. If the findings of the randomized part of the Precolos study indicate a positive effect of bovine colostrum and do not give rise to concerns regarding feasibility, safety or tolerability, a large-scale randomized controlled study with NEC as the primary outcome will be planned. Based on the high concentrations of bacteria found in the nasogastric feeding tubes, a randomized controlled trial investigating whether the frequency of feeding tube exchange affects the early colonization has been commenced in the neonatal department at Rigshospitalet. Hopefully, the results of these studies will bring us closer to preventing NEC in the future.