Study of the breast-milk microbiota in mothers of term vs. preterm infants in Argentina

ODDI, S.; MANTZIARI, ANASTASIA; BINETTI A; SALMINEN, S.; COLLADO, M.C.; VINDEROLA G.

Simposio; MIT Microbiome Symposium; 2021

Breast-milk is the gold standard for feeding infants and may favor the normal development of the gut-associated immune system. Globally, prematurity is the leading cause of death in children under the age of 5 years. Recent studies showed that breast milk between full-term and preterm infants differ not only on their nutritional composition but also on other compounds including microbiota, although the evidence is still limited. In this work, we analyzed the breast-milk microbiota profile from women with full-term and preterm deliveries g. Twelve mothers from each group (preterm: less than 37 weeks, and full-term: at least 37 weeks) were invited to donate breast-milk samples. In addition, from the preterm group, two samples were collected, one of them on the first days post-partum and another when infants reached 37 weeks of gestation or more. The 16S rRNA gene (V3-V4) amplification and Illumina sequencing were conducted. The alpha diversity (Simpson index) of the full-term group was significantly higher than the first sample of the preterm group, whereas no differences were observed when compared to the second sample of the preterm group. When the taxonomic composition of Firmicutes was considered, the breast-milk microbiota of the preterm group, gradually resembled that of the full-term group along days postpartum. The most abundant genera were Staphylococcus and Streptococcus (from the Firmicutes phylum), and they were also responsible for most of the differences observed. The rate of Streptococcus/Staphylococcus was higher in the full-term group than in the preterm group. Significantly lower levels of Rothia were observed in preterm milk samples than those observed in term milk samples. Preterm birth had a negative impact in microbiota diversity, but that gradually evolved along lactation to a composition resembling that of breast-milk from mothers that delivered fullterm. This is the first report of the composition of breast-milk in Argentina.