The influence of early-life microbial exposures on long-term respiratory health

Process and Outcome Measures for Infants Born Moderate and Late Preterm in Tertiary Canadian Neonatal Intensive Care Units

OBJECTIVE

To describe the prevalence of and between-center variations in care practices and clinical outcomes of moderate and late preterm infants (MLPIs) admitted to tertiary Canadian neonatal intensive care units (NICUs).

STUDY DESIGN

This was a retrospective cohort study including infants born at 320/7 through 366/7 weeks of gestation and admitted to 25 NICUs participating in the Canadian Neonatal Network between 2015 and 2020. Patient characteristics, process measures represented by care practices, and outcome measures represented by clinical in-hospital and discharge outcomes were reported by gestational age weeks. NICUs were compared using indirect standardization after adjustment for patient characteristics.

RESULTS

Among 25 669 infants (17% of MLPIs born in Canada during the study period) included, 45% received deferred cord clamping, 7% had admission hypothermia, 47% received noninvasive respiratory support, 11% received mechanical ventilation, 8% received surfactant, 40% received antibiotics in the first 3 days, 4% did not receive feeding in the first 2 days, and 77% had vascular access. Mortality, early-onset sepsis, late-onset sepsis, or necrotizing enterocolitis occurred in <1% of the study cohort. Median (IQR) length of stay was 14 (9-21) days among infants discharged home from the admission hospital and 5 (3-9) days among infants transferred to community hospitals. Among infants discharged home, 33% were discharged on exclusive breastmilk and 75% on any breastmilk. There were significant variations between NICUs in all process and outcome measures.

CONCLUSIONS

Care practices and outcomes of MLPIs varied significantly between Canadian NICUs. Standardization of process and outcome quality measures for this population will enable benchmarking and research, facilitating systemwide improvements.

The neonatal gut microbiome and global health

The role of gut microbiome in health, a century-old concept, has been on the center stage of medical research recently. While different body sites, disease conditions, and populations have been targeted, neonatal and early infancy appear to be the most suitable period for such interventions. It is intriguing to note that, unlike traditional use in diarrhea and maintenance of gastrointestinal health, microbiome-mediating therapies have now addressed the most serious medical conditions in young infants such as necrotizing enterocolitis and neonatal sepsis. Unfortunately, almost all new endeavors in this space have been carried out in the Western world leaving behind millions of neonates that can benefit from such manipulations while serving as a large resource for further learning. In this review, an attempt has been made to quantify the global burden of neonatal morbidity and mortality, examples presented on interventions that have failed as a result of drawing from studies conducted in the West, and a case made for manipulating the neonatal gut microbiome to address the biggest killers in early life. A brief comparative analysis has been made to demonstrate the differences in the gut microbiota of North and South and a large clinical trial of synbiotics conducted by our group in a South Asian setting has been presented. Although challenging, the value of conducting such global health research is introduced with an intent to invite medical scientists to engage in well-planned, scientifically robust research endeavors. This can bring about innovation while saving and serving the most vulnerable citizens now and protecting them from the negative health consequences in the later part of their lives, ultimately shaping a resilient and equitable world as pledged by 193 United Nations member countries in 2015.

Development of Early-Life Gastrointestinal Microbiota in the Presence of Antibiotics Alters the Severity of Acute DSS-Induced Colitis in Mice

Early-life gastrointestinal microbiota development is crucial for physiological development and immunological homeostasis. In the current study, perinatal microbiota and the development of gastrointestinal microbiota in different early-life periods (perinatal, lactation, and postweaning nutrition periods) were explored by using an antibiotic-interfered mouse model and a dextran sulfate sodium-induced colitis mouse model. Gut microbiota samples were collected from mother mice and litters. The results of 16S rRNA gene sequences suggested that microbiota in the gastrointestinal system were present in prenatal fetal mice, and microbiota structures in different parts of the gastrointestinal system of the fetal mice were similar to those in the corresponding gut parts of maternal mice. Microbiota in mucus samples from different regions exhibited higher diversity at birth than at other periods and varied substantially over time with diet change. Moreover, antibiotic treatment in early life affected the composition and diversity of gastrointestinal microbiota in adult mice and enhanced susceptibility to experimental colitis in mice, particularly in the lactation period. This approach of exploring gut microbiota evolution is hoped to provide an enhanced view of how resident microbiota develop in early life, which in turn might facilitate understanding of gut microbiota and related diseases. IMPORTANCE This study investigated resident microbiota in the whole gastrointestinal (GI) tract to explore gut microbiota development in early life and found that early-life antibiotic exposure exacerbated alterations in gut microbiota and murine dextran sulfate sodium (DSS)-induced colitis. Furthermore, the presence of bacteria in the GI tract of mice before birth and the importance of the lactation period in GI microbiota development were confirmed.