Objective

Chorioamnionitis (inflammation of the placenta and fetal membranes) and abnormal gastrointestinal colonization have been associated with an increased risk of sepsis and death in preterm infants, but whether chorioamnionitis causes abnormal pioneering gastrointestinal colonization in infants is not known. We determined the relationship between chorioamnionitis, altered infant fecal microbiome indicating abnormal gastrointestinal colonization, and adverse outcomes.

Study design

Preterm infants ≤ 28 weeks at birth were enrolled from 3 level III NICUs in Cincinnati, Ohio and Birmingham, Alabama. Sequencing for 16S microbial gene was performed on stool samples in the first 3 weeks of life. Chorioamnionitis was diagnosed by placental histology. Late onset sepsis and death outcomes were analyzed in relation to fecal microbiota and chorioamnionitis with or without funisitis (inflammation of the umbilical cord).

Results

Of the 106 enrolled infants, 48 infants had no chorioamnionitis, 32 infants had chorioamnionitis but no funisitis (AC), and 26 infants had chorioamnionitis with funisitis (ACF). The fecal samples from ACF infants collected by day of life 7 had higher relative abundance of family Mycoplasmataceae (phylum Tenericutes), genus Prevotella (phylum Bacteroidetes) and genus Sneathia (phylum Fusobacteria). Further, AC and ACF infants had higher incidence of late-onset sepsis/death as a combined outcome. Presence of specific clades in fecal samples, specifically, order Fusobacteria, genus Sneathia or family Mycoplasmataceae, were significantly associated with higher risk of sepsis or death.

Conclusion

The results support the hypothesis that specific alterations in the pioneering infant gastrointestinal microbiota induced by chorioamnionitis predispose to neonatal sepsis or death.

Background: Black mothers in the United States have shorter breastfeeding (BF) durations and less exclusive breastfeeding (EBF) than others. The factors underlying these disparities require investigation. Methods: Using longitudinal data from a CDC-sponsored birth cohort in Cincinnati, Ohio, we analyzed the factors mediating racial disparity in BF outcomes. Study mothers were enrolled in prenatal clinics associated with two large birth hospitals. Analysis was restricted to racial groups with sufficient numbers in the cohort, non-Hispanic Black (n = 92) and White (n = 113) mothers, followed to at least 6 months postpartum. Results: Black mothers were 25 times more likely to reside in socioeconomically deprived neighborhoods and 20 times more likely to have an annual household income <$50,000/year than White mothers (p < 0.001). The gap in EBF for 6 weeks was 45 percentage points by racial group (13%-Black mothers versus 58%-White mothers, p < 0.001); in any BF at 6 months was 37 percentage points (28%-Black mothers versus 65%-White mothers, p < 0.001); and in mothers meeting their own intention to BF at least 6 months was 51 percentage points (29%-Black mothers versus 80%-White mothers, p < 0.001). Racial disparity in EBF at 6 weeks was mediated in logistic regression models by inequities in socioeconomic position, maternal hypertension, and BF intention. Racial disparities in BF at 6 months or meeting 6-month BF intention were mediated by inequities in socioeconomic position, maternal obesity, and EBF at 6 weeks. Not all BF disparities could be explained by models used in these analyses. Conclusions: Efforts to lessen BF disparities should address the underlying structural inequities that disproportionately affect Black mothers and children, should incorporate maternal health, and focus on breastfeeding exclusivity and duration. Few Black mothers achieved EBF at 6 weeks, which contributed to disparity in BF duration. Greater attention to Black mother-infant pairs is a public health priority.

Bifidobacterium species are beneficial and dominant members of the breastfed infant gut microbiome; however, their health benefits are partially species-dependent. Here, we characterize the species and subspecies of Bifidobacterium in breastfed infants around the world to consider the potential impact of a historic dietary shift on the disappearance of B. longum subsp. infantis in some populations. Across populations, three distinct patterns of Bifidobacterium colonization emerged: (1) The dominance of Bifidobacterium longum subspecies infantis, (2) prevalent Bifidobacterium of multiple species, and (3) the frequent absence of any Bifidobacterium. These patterns appear related to a country's history of breastfeeding, with infants in countries with historically high rates of long-duration breastfeeding more likely to be colonized by B. longum subspecies infantis compared with infants in countries with histories of shorter-duration breastfeeding. In addition, the timing of infant colonization with B. longum subsp. infantis is consistent with horizontal transmission of this subspecies, rather than the vertical transmission previously reported for other Bifidobacterium species. These findings highlight the need to consider historical and cultural influences on the prevalence of gut commensals and the need to understand epidemiological transmission patterns of Bifidobacterium and other major commensals.

Nationally representative data from mother-child dyads that capture human milk composition (HMC) and associated health outcomes are important for advancing the evidence to inform federal nutrition and related health programs, policies, and consumer information across the governments in the United States and Canada as well as in nongovernment sectors. In response to identified gaps in knowledge, the National Institute of Diabetes and Digestive and Kidney Diseases of the NIH sponsored the Workshop on Human Milk Composition-Biological, Environmental, Nutritional, and Methodological Considerations held 16-17 November 2017 in Bethesda, Maryland. Through presentations and discussions, the workshop aimed to 1) share knowledge on the scientific need for data on HMC; 2) explore the current understanding of factors affecting HMC; 3) identify methodological challenges in human milk (HM) collection, storage, and analysis; and 4) develop a vision for a research program to develop an HMC data repository and database. The 4 workshop sessions included 1) perspectives from both federal agencies and nonfederal academic experts, articulating scientific needs for data on HMC that could lead to new research findings and programmatic advances to support public health; 2) information about the factors that influence lactation and/or HMC; 3) considerations for data quality, including addressing sampling strategies and the complexities in standardizing collection, storage, and analyses of HM; and 4) insights on how existing research programs and databases can inform potential visions for HMC initiatives. The general consensus from the workshop is that the limited scope of HM research initiatives has led to a lack of robust estimates of the composition and volume of HM consumed and, consequently, missed opportunities to improve maternal and infant health.

This paper resulted from a conference entitled "Lactation and Milk: Defining and refining the critical questions" held at the University of Colorado School of Medicine from January 18-20, 2012. The mission of the conference was to identify unresolved questions and set future goals for research into human milk composition, mammary development and lactation. We first outline the unanswered questions regarding the composition of human milk (Section I) and the mechanisms by which milk components affect neonatal development, growth and health and recommend models for future research. Emerging questions about how milk components affect cognitive development and behavioral phenotype of the offspring are presented in Section II. In Section III we outline the important unanswered questions about regulation of mammary gland development, the heritability of defects, the effects of maternal nutrition, disease, metabolic status, and therapeutic drugs upon the subsequent lactation. Questions surrounding breastfeeding practice are also highlighted. In Section IV we describe the specific nutritional challenges faced by three different populations, namely preterm infants, infants born to obese mothers who may or may not have gestational diabetes, and infants born to undernourished mothers. The recognition that multidisciplinary training is critical to advancing the field led us to formulate specific training recommendations in Section V. Our recommendations for research emphasis are summarized in Section VI. In sum, we present a roadmap for multidisciplinary research into all aspects of human lactation, milk and its role in infant nutrition for the next decade and beyond.