The first fungi: mode of delivery determines early life fungal colonization in the intestine of preterm infants.

Aim: The role of intestinal fungi in human health and disease is becoming more evident. The mycobiota composition and diversity of preterm infants is affected by interactions with bacteria and clinical variables. In this study, we aimed to characterize the composition and the diversity of the preterm infant mycobiota and the effect of clinical variables on it in the first six postnatal weeks. Methods: Preterm infants (n = 50) and full-term infants (n = 6) admitted to Isala Women and Children's hospital (Zwolle, The Netherlands) who were born during 24-36 or 37-40 weeks of gestation, respectively, were included in this study. Feces were collected during the first six postnatal weeks (n = 109) and their mycobiota composition and diversity were characterized by ITS2 amplicon sequencing. Results: Composition analyses identified fungi and other eukaryotic kingdoms, of which Viridiplantae was most abundant. Of the fungal kingdom, Ascomycota and Basidiomycota were the first and second most prominent phyla in early life of all infants. Candida was the most abundant genus in the first six weeks of life and increased with gestational and postnatal age. Fungal phylogenetic diversity remained stable in the first six postnatal weeks. The individuality and the mode of delivery were identified as significant predictors for the variation in the mycobiota composition. Vaginally delivered infants were enriched in Candida spp., whereas infants delivered through emergency C-section were characterized by Malassezia spp. Conclusion: These results indicate that fungi and other eukaryotic kingdoms are detected in the intestine of preterm and full-term infants in the first six postnatal weeks. Similar to the microbiota, colonization of the preterm intestine with fungi is determined by clinical variables including individuality and mode of delivery.

Maturation of the preterm gastrointestinal tract can be defined by host and microbial markers for digestion and barrier defense.

Functionality of the gastrointestinal tract is essential for growth and development of newborns. Preterm infants have an immature gastrointestinal tract, which is a major challenge in neonatal care. This study aims to improve the understanding of gastrointestinal functionality and maturation during the early life of preterm infants by means of gastrointestinal enzyme activity assays and metaproteomics. In this single-center, observational study, preterm infants born between 24 and 33 weeks (n = 40) and term infants born between 37 and 42 weeks (n = 3), who were admitted to Isala (Zwolle, the Netherlands), were studied. Enzyme activity analyses identified active proteases in gastric aspirates of preterm infants. Metaproteomics revealed human milk, digestive and immunological proteins in gastric aspirates of preterm infants and feces of preterm and term infants. The fecal proteome of preterm infants was deprived of gastrointestinal barrier-related proteins during the first six postnatal weeks compared to term infants. In preterm infants, bacterial oxidative stress proteins were increased compared to term infants and higher birth weight correlated to higher relative abundance of bifidobacterial proteins in postnatal week 3 to 6. Our findings indicate that gastrointestinal and beneficial microbial proteins involved in gastrointestinal maturity are associated with gestational and postnatal age.

Dynamics of the bacterial gut microbiota in preterm and term infants after intravenous amoxicillin/ceftazidime treatment.

BACKGROUND: It is important to understand the consequences of pre-emptive antibiotic treatment in neonates, as disturbances in microbiota development during this key developmental time window might affect early and later life health outcomes. Despite increasing knowledge regarding the detrimental effect of antibiotics on the gut microbiota, limited research focussed on antibiotic treatment duration. We determined the effect of short and long amoxicillin/ceftazidime administration on gut microbiota development during the immediate postnatal life of preterm and term infants. METHODS: Faeces was collected from 63 (pre) term infants at postnatal weeks one, two, three, four and six. Infants received either no (control), short-term (ST) or long-term (LT) postpartum amoxicillin/ceftazidime treatment. RESULTS: Compared to control infants, ST and LT infants' microbiota contained significantly higher abundance of Enterococcus during the first two postnatal weeks at the expense of Bifidobacterium and Streptococcus. Short and long antibiotic treatment both allowed for microbiota restoration within the first six postnatal weeks. However, Enterococcus and Bifidobacterium abundances were affected in fewer ST than LT infants. CONCLUSIONS: Intravenous amoxicillin/ceftazidime administration affects intestinal microbiota composition by decreasing the relative abundance of Escherichia-Shigella and Streptococcus, while increasing the relative abundance of Enterococcus and Lactobacillus species during the first two postnatal weeks. Thriving of enterococci at the expense of bifidobacteria and streptococci should be considered as aspect of the cost-benefit determination for antibiotic prescription.

Association between duration of intravenous antibiotic administration and early-life microbiota development in late-preterm infants.

Antibiotic treatment is common practice in the neonatal ward for the prevention and treatment of sepsis, which is one of the leading causes of mortality and morbidity in preterm infants. Although the effect of antibiotic treatment on microbiota development is well recognised, little attention has been paid to treatment duration. We studied the effect of short and long intravenous antibiotic administration on intestinal microbiota development in preterm infants. Faecal samples from 15 preterm infants (35 ± 1 weeks gestation and 2871 ± 260 g birth weight) exposed to no, short (≤ 3 days) or long (≥ 5 days) treatment with amoxicillin/ceftazidime were collected during the first six postnatal weeks. Microbiota composition was determined through 16S rRNA gene sequencing and by quantitative polymerase chain reaction (qPCR). Short and long antibiotic treat ment significantly lowered the abundance of Bifidobacterium right after treatment (p = 0.027) till postnatal week three (p = 0.028). Long treatment caused Bifidobacterium abundance to remain decreased till postnatal week six (p = 0.009). Antibiotic treatment was effective against members of the Enterobacteriaceae family, but allowed Enterococcus to thrive and remain dominant for up to two weeks after antibiotic treatment discontinuation. Community richness and diversity were not affected by antibiotic treatment, but were positively associated with postnatal age (p < 0.023) and with abundance of Bifidobacterium (p = 0.003). Intravenous antibiotic administration during the first postnatal week greatly affects the infant's gastrointestinal microbiota. However, quick antibiotic treatment cessation allows for its recovery. Disturbances in microbiota development caused by short and, more extensively, by long antibiotic treatment could affect healthy development of the infant via interference with maturation of the immune system and gastrointestinal tract.

Metaproteomics reveals functional differences in intestinal microbiota development of preterm infants.

OBJECTIVE: Development of the gastrointestinal tract and immune system can be modulated by the gut microbiota. Establishment of the intestinal microbiota, in its turn, is affected by host and environmental factors. As such, development of the gut microbiota is greatly impacted in preterm infants, who have an immature gut and are exposed to factors like hospitalization, caesarean section, antibiotics, and respiratory support. DESIGN: We analyzed fecal microbiota composition and activity of ten preterm infants (gestational age 25-30 weeks; birthweight 630-1750 g) during the first six postnatal weeks through metaproteomics (LC-MS/MS) and 16S-rRNA gene sequencing. RESULTS: A gestational-age-dependent microbial signature is observed, enabling microbiota-based differentiation between extremely preterm (25-27 weeks gestation) and very preterm (30 weeks gestation) infants. In very preterm infants, the intestinal microbiota developed toward a Bifidobacterium-dominated community and was associated with high abundance of proteins involved in carbohydrate and energy metabolism. Extremely preterm infants remained predominantly colonized by facultative anaerobes and were associated with proteins involved in membrane transport and translation. Delayed colonization by obligate anaerobes could be associated with antibiotic treatment and respiratory support. CONCLUSION: We speculate that gestational age and its associated intensity of care (e.g. antibiotics and respiratory support) affects intestinal microbiota composition and activity in preterm infants. As the gut microbiota plays a major role in development of the neonate, gestational age and its associated factors could set the stage for early and later life health complications via interference with microbiota development.

Effect of Donor Milk on Severe Infections and Mortality in Very Low-Birth-Weight Infants: The Early Nutrition Study Randomized Clinical Trial.

IMPORTANCE: Infections and necrotizing enterocolitis, major causes of mortality and morbidity in preterm infants, are reduced in infants fed their own mother's milk when compared with formula. When own mother's milk is not available, human donor milk is considered a good alternative, albeit an expensive one. However, most infants at modern neonatal intensive care units are predominantly fed with own mother's milk. The benefits of add-on donor milk over formula are not clear. OBJECTIVE: To determine whether providing donor milk instead of formula as supplemental feeding whenever own mother's milk is insufficiently available during the first 10 days of life reduces the incidence of serious infection, necrotizing enterocolitis, and mortality. DESIGN, SETTINGS, AND PARTICIPANTS: The Early Nutrition Study was a multicenter, double-blind randomized clinical trial in very low-birth-weight infants (birth weight <1500 g) admitted to 1 of 6 neonatal intensive care units in the Netherlands from March 30, 2012, through August 17, 2014. Intent-to-treat analysis was performed. INTERVENTIONS: Infants received pasteurized donor milk or preterm formula during the first 10 days of life if own mother's milk was not (sufficiently) available. MAIN OUTCOMES AND MEASURES: The primary end point was cumulative occurrence of serious infection (sepsis or meningitis), necrotizing enterocolitis, or mortality during the first 60 days of life. RESULTS: A total of 930 infants were screened for inclusion; 557 were excluded, resulting in 373 infants (183 receiving donor milk and 190 receiving formula) who were evaluated by intent-to-treat analysis (median birth weight, 1066 g; mean gestational age, 28.4 weeks). Own mother's milk comprised 89.1% and 84.5% of total mean intake during the intervention period for the donor milk and formula groups, respectively. The incidence of the combined outcome was not different (85 [44.7%] [formula] vs 77 [42.1%] [donor milk]; mean difference, 2.6%; 95% CI, -12.7% to 7.4%). The adjusted hazard ratio was 0.87 (95% CI, 0.63-1.19; P = .37). CONCLUSIONS AND RELEVANCE: In the current study, pasteurized donor milk and preterm formula as supplemental feeding during the first 10 days of life yielded similar short-term outcomes in very low-birth-weight infants regarding safety and efficacy when own mother's milk availability was insufficient. Future studies investigating longer duration of use of human donor milk on short-term and long-term outcomes are necessary. TRIAL REGISTRATION: trialregister.nl Identifier: NTR3225.

Antioxidant role of plasma carotenoids in bronchopulmonary dysplasia in preterm infants.

OBJECTIVES: Oxidative stress is implicated in the pathogenesis of bronchopulmonary dysplasia (BPD) and consequently, it might be theorized that sufficient antioxidant defenses are needed to prevent BPD. We hypothesized that, except for vitamins E and A, carotenoids may be important in this defense. Carotenoids are present in human milk; however, they are not added to parenteral nutrition, the main food source of preterm infants in the first week of life. AIM: To evaluate prospectively the role of carotenoids in BPD in a cohort of preterm infants. METHODS: The plasma concentrations of F(2alpha)-isoprostane, alpha- and beta-carotene, lycopene, lutein, vitamin A, and the vitamin E/cholesterol ratio were studied at days 1, 3, and 7 in a cohort of 109 preterm infants, of whom 19 had BPD. RESULTS: When comparing the BPD and control group, infants in the BPD group were younger (p<0.001) and beta-carotene (day 7, p<0.01) and vitamin A concentrations were lower (days 3 and 7, p<0.001). Lycopene, lutein, alpha-carotene, vitamin E, and F(2alpha)-isoprostane concentrations did not differ between groups. CONCLUSIONS: Plasma beta-carotene and vitamin A concentrations are lower in BPD infants which may result in a reduction of their antioxidant protection.