Intestinal microbiota development and weight gain in preterm neonates

Abstract

[Introduction] Bacterial colonization of the intestine in the neonatal period is of key importance for the correct maturation and development of the newborn. Different studies have suggested a role of the intestinal microbiota in energy-harvesting and weight-gain in adults. However, the potential associations between the early microbiota composition and weight-gain in preterm neonates have not been explored. [Objectives] To determine the potential associations existing between the early intestinal microbiota and weight-gain during the first months of life in preterm infants. [Subjects and Methods] The intestinal microbial colonization was followed in 63 preterm newborns (less than 36 weeks gestational age; mean 30.7 weeks). The levels of specific microbial groups (Bifidobacterium, Staphylococcus, Enterococcus, Streptococcus, Weissella, Enterobacteriaceae, Bacteroides and Lactobacillus) were determined by qPCR in faecal samples taken at 2, 10, 30 and 90 days of age. The level of faecal short chain fatty acids was evaluated as well by means of Gas Chromatography. The weight-gain (expressed as percentage of birth-weight) of each infant was calculated at 10, 30 and 90 days of age. [Results] The statistical analyses of the data revealed significant associations (p<0.05) between weightgain and specific microbial groups, at different time points analyzed. The levels of Bifidobacterium and Streptococcus at 10 and 30 days, but not at 2 days of age, showed a positive correlation with weight-gain during the first months of life in premature infants. Although it is not possible to establish a causal relationship, the identification of correlations between early samples’ microbiota and later weight-gain suggest a potential role for the microbiota and its potential use as an infant maturation marker of prognostic value. [Conclusion] The data obtained suggest a relationship between early microbiota establishment and weight-gain in preterm newborns.