Human milk microbiota associated with early colonization of the neonatal gut in Mexican newborns

PeerJ. 2020 May 22:8:e9205. doi: 10.7717/peerj.9205. eCollection 2020.

Abstract

Background: Human milk microbiota plays a role in the bacterial colonization of the neonatal gut, which has important consequences in the health and development of the newborn. However, there are few studies about the vertical transfer of bacteria from mother to infant in Latin American populations.

Methods: We performed a cross-sectional study characterizing the bacterial diversity of 67 human milk-neonatal stool pairs by high-throughput sequencing of V3-16S rDNA libraries, to assess the effect of the human milk microbiota on the bacterial composition of the neonate's gut at early days.

Results: Human milk showed higher microbial diversity as compared to the neonatal stool. Members of the Staphylococcaceae and Sphingomonadaceae families were more prevalent in human milk, whereas the Pseudomonadaceae family, Clostridium and Bifidobacterium genera were in the neonatal stool. The delivery mode showed association with the neonatal gut microbiota diversity, but not with the human milk microbiota diversity; for instance, neonates born by C-section showed greater richness and diversity in stool microbiota than those born vaginally. We found 25 bacterial taxa shared by both ecosystems and 67.7% of bacteria found in neonate stool were predicted to originate from human milk. This study contributes to the knowledge of human milk and neonatal stool microbiota in healthy Mexican population and supports the idea of vertical mother-neonate transmission through exclusive breastfeeding.

Keywords: 16S rDNA; Breastfeeding; Delivery mode; High-throughput DNA sequencing; Human milk; Ion Torrent; Mexican mother; Microbiota; Neonatal gut microbiota.

Grants and funding

This work was supported by Cinvestav, CONACyT-163235 INFR-2011-01, Fondo SEP-Cinvestav-2018-174, CONACyT Post-Doctoral Fellowship 398875 (IGG), and CONACyT Doctoral Fellowship 777953 (KCC). Ciudad Sen S. de R. L. de C. V. provided funds for the publication fee. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.