Changes in the Bacterial Diversity of Human Milk during Late Lactation Period (Weeks 21 to 48)

• Main Authors: Wendy Marin-Gómez, Mᵃ José Grande, Rubén Pérez-Pulido, Antonio Galvez, Rosario Lucas
• Format: Article
• Language: English
• Published: MDPI AG 2020-08-01
• Series: Foods
• Subjects: breast milk; biodiversity; lactic acid bacteria; late lactation; metagenomics
• Online Access: https://www.mdpi.com/2304-8158/9/9/1184

Breast milk from a single mother was collected during a 28-week lactation period. Bacterial diversity was studied by amplicon sequencing analysis of the V3-V4 variable region of the 16S rRNA gene. <i>Firmicutes</i> and <i>Proteobacteria</i> were the main phyla detected in the milk samples, followed by <i>Actinobacteria</i> and <i>Bacteroidetes</i>. The proportion of <i>Firmicutes</i> to <i>Proteobacteria</i> changed considerably depending on the sampling week. A total of 411 genera or higher taxons were detected in the set of samples. Genus <i>Streptococcus</i> was detected during the 28-week sampling period, at relative abundances between 2.0% and 68.8%, and it was the most abundant group in 14 of the samples. <i>Carnobacterium</i> and <i>Lactobacillus</i> had low relative abundances. At the genus level, bacterial diversity changed considerably at certain weeks within the studied period. The weeks or periods with lowest relative abundance of <i>Streptococcus</i> had more diverse bacterial compositions including genera belonging to <i>Proteobacteria</i> that were poorly represented in the rest of the samples.