Sakwinska O, Moine D, Delley M, Combremont S, Rezzonico E, Descombes P, Vinyes-Pares G, Zhang Y, Wang P, Thakkar SK
Numerous studies have reported the presence of bacteria in breast milk. Although the initial focus was on detection of potential pathogens, there is increasing evidence that the presence of bacteria in different niches of the human body is the physiological norm. Therefore, there is interest in characterizing milk microbiota and studying their potential benefits for the breastfed infant. Previous data obtained from American and European women suggest that geographical and ethnical differences may play a role on milk microbiota composition, in addition, the methodologies used for analysis and milk collection can account for some variability. Most studies have collected milk in aseptic conditions, and only a few have analyzed samples collected by standard methods (without previous cleansing).
This study explored the microbiota from Chinese mothers at three time points within the first 2 months of lactation and compared samples collected with aseptic vs standard procedures. The total amount of bacteria was higher with standard than in aseptic collection. In accordance to what has been reported in other geographical regions, staphylococci and streptococci dominated breast milk microbiota from Chinese women and constituted 42 and 40% of total bacteria. Acinetobacter sp was very abundant in standard collection samples representing an average of 32% of the total, but not by aseptic procedures where it was only 1.8%. Lactobacilli and bifidobacteria were present only in few samples with low abundance (less than 1%) in both, aseptic and standard collected samples.
There was no impact on delivery mode or stage of lactation in the samples studied. This study provides further evidence on the presence of bacteria in human milk and data on the milk microbiota of Chinese women. In addition, the authors suggest the name ‘Breastfeeding-associated microbiota’ to that found in standard collected samples which is more representative of the microbiota that the infant ingest.
Published online 2016 Aug 16. doi: 10.1371/journal.pone.0160856.