Bacterial Composition and Diversity in Breast Milk Samples from Mothers Living in Taiwan and Mainland China

Abstract

Human breast milk is widely recognized as the best source of nutrients for healthy growth and development of infants; it contains a diverse microbiota. Here, we characterized the diversity of the microbiota in the breast milk of East Asian women and assessed whether delivery mode influenced the microbiota in the milk of healthy breast-feeding mothers. We profiled the microbiota in breast milk samples collected from 133 healthy mothers in Taiwan and in six regions of mainland China (Central, East, North, Northeast, South, and Southwest China) by using 16S rRNA pyrosequencing. Lactation stage (months postpartum when the milk sample was collected) and maternal body mass index did not influence the breast milk microbiota. Bacterial composition at the family level differed significantly among samples from the seven geographical regions. The five most predominant bacterial families were Streptococcaceae (mean relative abundance: 24.4%), Pseudomonadaceae (14.0%), Staphylococcaceae (12.2%), Lactobacillaceae (6.2%), and Oxalobacteraceae (4.8%). The microbial profiles were classified into three clusters, driven by Staphylococcaceae (abundance in Cluster 1: 42.1%), Streptococcaceae (Cluster 2: 48.5%), or Pseudomonadaceae (Cluster 3: 26.5%). Microbial network analysis at the genus level revealed that the abundances of the Gram-positive Staphylococcus, Streptococcus, and Rothia were negatively correlated with those of the Gram-negative Acinetobacter, Bacteroides, Halomonas, Herbaspirillum, and Pseudomonas. Milk from mothers who had undergone Caesarian section (C-section group) had a significantly higher abundance of Lactobacillus (P < 0.05) and a higher number of unique unclassified operational taxonomic units (OTUs) (P < 0.001) than that from mothers who had undergone vaginal delivery (vaginal group). These findings revealed that (i) geographic differences in the microbial profiles were found in breast milk from mothers living in Taiwan and mainland China, (ii) the predominant bacterial families Streptococcaceae, Staphylococcaceae, and Pseudomonadaceae were key components for forming three respective clusters, and (iii) a significantly greater number of unique OTUs was found in the breast milk from mothers who had undergone C-section than from those who had delivered vaginally.

Microbial Communities in Human Milk Relate to Measures of Maternal Weight

“…While the average abundance of these four microbes are similar across all samples, two clusters each were characterized by higher abundances of Streptococcus and Staphylococcus, or Pseudomonas and Acinetobacter with differences in alpha diversity and the abundances of numerous other taxa further differentiating these clusters. The clusters we identified share both similarities and differences with the breast milk microbiome clusters identified in Chinese (Li et al, 2017), Italian (Biagi et al, 2018), and Canadian (Moossavi et al, 2019b) mothers, suggesting that some patterns of microbial populations in human milk may be similar amongst geographically and racially distinct populations. Bacteria belonging to the genera Acinetobacter and Pseudomonas are often thought of as pathogens contributing to nosocomial infections (Fazeli et al, 2012;Custovic et al, 2014).…”

“…Preliminary small studies using 16S rRNA gene sequencing and metagenomics approaches to assess breast milk microbial composition have reported that Streptococcus, Staphylococcus, Pseudomonas, Bacteroides, Acinetobacter, and others comprise the core breast milk microbiome, whereas Bifidobacterium and Lactobacillus abundances are comparatively low (Hunt et al, 2011;Jost et al, 2013;Ward et al, 2013;Jiménez et al, 2015;Sakwinska et al, 2016;Urbaniak et al, 2016;Murphy et al, 2017). Clusters of breast milk microbiota have been reported, often defined by the abundance of Staphylococcus, Streptococcus, and Pseudomonas, Enterobacteriaceae, and other rarer bacteria (Li et al, 2017;Biagi et al, 2018;Moossavi et al, 2019b).…”

Mycobiome Profiles in Breast Milk from Healthy Women Depend on Mode of Delivery, Geographic Location, and Interaction with Bacteria

“…In addition, accumulating evidence suggests that some environmental factors might influence breast milk composition (25)(26)(27). In particular, geographic location, delivery mode, maternal body mass index (BMI), and age have been suggested to have an impact on breast milk bacterial composition (28)(29)(30)(31)(32)(33)(34)(35), although their potential impact on the milk's fungal fraction is still to be elucidated.…”

Human behavior, not race or geography, is the strongest predictor of microbial succession in the gut bacteriome of infants

“…The second cross-cultural study supporting the notion that individual variations in breast milk bacteria may be influenced by geographic location compared milk samples collected from different regions in East Asia. 65 In this study, milk samples were compared using 454 pyrosequencing of 16 S rRNA genes between Taiwan and six-regions of mainland China. The relative abundance of Pseudomonadaceae was found to be lower in samples from Taiwan (n = 31) compared to East (n = 34), Central (n = 24) and Northeast (n = 17) China.…”