School of Chemistry and Molecular Biosciences, The University of Queensland, Saint Lucia, QLD 4072, Australia.
Pregnancy and Development Group, Mater Research Institute, South Brisbane, QLD 4101, Australia.
Nutrients. 2023 Jan 30;15(3):696. doi: 10.3390/nu15030696.
Breastmilk is thought to influence the infant gut by supplying prebiotics in the form of human milk oligosaccharides and potentially seeding the gut with breastmilk microbes. However, the presence of a breastmilk microbiota and origins of these microbes are still debated. As a pilot study, we assessed the microbes present in expressed breastmilk at six-weeks postpartum using shotgun metagenomic sequencing in a heterogenous cohort of women who delivered by vaginal (n = 8) and caesarean delivery (n = 8). In addition, we estimated the microbial load of breastmilk at six-weeks post-partum with quantitative PCR targeting the 16S rRNA gene. Breastmilk at six-weeks postpartum had a low microbial mass, comparable with PCR no-template and extraction controls. Microbes identified through metagenomic sequencing were largely consistent with skin and oral microbes, with four samples returning no identifiable bacterial sequences. Our results do not provide convincing evidence for the existence of a breastmilk microbiota at six-weeks postpartum. It is more likely that microbes present in breastmilk are sourced by ejection from the infant's mouth and from surrounding skin, as well as contamination during sampling and processing.
母乳被认为通过提供人乳寡糖形式的益生元,并可能通过母乳微生物来定植肠道,从而影响婴儿的肠道。然而,母乳微生物群的存在及其微生物的来源仍存在争议。作为一项初步研究,我们使用阴道分娩(n=8)和剖宫产(n=8)的异质队列中的女性在产后 6 周时使用鸟枪法宏基因组测序来评估母乳中存在的微生物。此外,我们通过针对 16S rRNA 基因的定量 PCR 来估计产后 6 周时母乳的微生物负荷。产后 6 周的母乳微生物量很低,与 PCR 无模板和提取对照相当。通过宏基因组测序鉴定的微生物与皮肤和口腔微生物基本一致,有 4 个样本未返回可识别的细菌序列。我们的结果并没有为产后 6 周存在母乳微生物群提供令人信服的证据。更有可能的是,母乳中存在的微生物是通过婴儿口腔和周围皮肤的排出以及在采样和处理过程中的污染而来的。