The gut microbiome plays a critical role in the healthy development, immunity and metabolism of infants. Preterm birth disrupts microbiome development and can contribute to acute and chronic disease. To promote microbial and infant development, and to mitigate the risk of disease, premature infants may be treated with probiotics. Here we used 16S rRNA high throughout sequencing to characterize the bacterial microbiome of probiotic-supplemented premature infants. The study aimed to identify and understand variation in bacterial gut flora, including changes from admission to discharge, and the effect of several clinical variables using a combination of univariate and mixed effects analyses.
Infants born <32 weeks gestation and <1500 g were recruited in North Queensland, Australia, with faecal samples collected at admission (n = 71) and at discharge (n = 63). Our research builds on previous research and supports significant changes over time in the preterm infant microbiome, and in response to several variables. Univariate analysis showed admission and discharge samples had significantly different microbial populations, with Staphylococcus enriched at admission and Enterobacter, Lactobacillus, Colstridium sensu stricto 1 and Veillonella at discharge. From the mixed effects modeling we observed significantly lower alpha diversity in infants diagnosed with either sepsis or retinopathy of prematurity (ROP), and those that only received formula milk. Chorioamnionitis, preeclampsia, sepsis, necrotizing enterocolitis and ROP were also all associated with differential abundance of several taxa.
Our study builds on previous research and supports significant changes in the preterm microbiome over time and in association with several factors. The fact that several associations were observed, and some in ways that counter previous work, highlights the complexity of microbiome ecology.