Sitarik Alexandra R, Bobbitt Kevin R, Havstad Suzanne L, Fujimura Kei E, Levin Albert M, Zoratti Edward M, Kim Haejin, Woodcroft Kimberley J, Wegienka Ganesa, Ownby Dennis R, Joseph Christine L M, Lynch Susan V, Johnson Christine C
*Department of Public Health Sciences, Henry Ford Health System, Detroit, MI †Division of Gastroenterology, University of California, San Francisco, CA ‡Department of Internal Medicine, Division of Allergy and Immunology, Henry Ford Health System, Detroit, MI §Department of Pediatrics, Georgia Regents University, Augusta, GA.
J Pediatr Gastroenterol Nutr. 2017 Sep;65(3):e60-e67. doi: 10.1097/MPG.0000000000001585.
Breast milk is a complex bioactive fluid that varies across numerous maternal and environmental conditions. Although breast-feeding is known to affect neonatal gut microbiome, the milk components responsible for this effect are not well-characterized. Given the wide range of immunological activity breast milk cytokines engage in, we investigated 3 essential breast milk cytokines and their association with early life gut microbiota.
A total of 52 maternal-child pairs were drawn from a racially diverse birth cohort based in Detroit, Michigan. Breast milk and neonatal stool specimens were collected at 1-month postpartum. Breast milk transforming growth factor (TGF)β1, TGFβ2, and IL-10 were assayed using enzyme-linked immunosorbent assays, whereas neonatal gut microbiome was profiled using 16S rRNA sequencing.
Individually, immunomodulators TGFβ1 and TGFβ2 were significantly associated with neonatal gut microbial composition (R = 0.024, P = 0.041; R = 0.026, P = 0.012, respectively) and increased richness, evenness, and diversity, but IL-10 was not. The effects of TGFβ1 and TGFβ2, however, were not independent of one another, and the effect of TGFβ2 was stronger than that of TGFβ1. Higher levels of TGFβ2 were associated with the increased relative abundance of several bacteria, including members of Streptococcaceae and Ruminococcaceae, and lower relative abundance of distinct Staphylococcaceae taxa.
Breast milk TGFβ concentration explains a portion of variability in gut bacterial microbiota composition among breast-fed neonates. Whether TGFβ acts in isolation or jointly with other bioactive components to alter bacterial composition requires further investigation. These findings contribute to an increased understanding of how breast-feeding affects the gut microbiome-and potentially immune development-in early life.
母乳是一种复杂的生物活性液体，会因众多母体和环境条件而有所不同。尽管已知母乳喂养会影响新生儿肠道微生物群，但造成这种影响的乳汁成分尚未得到充分表征。鉴于母乳细胞因子具有广泛的免疫活性，我们研究了3种重要的母乳细胞因子及其与早期肠道微生物群的关联。
从密歇根州底特律市一个种族多样的出生队列中选取了52对母婴。产后1个月收集母乳和新生儿粪便样本。采用酶联免疫吸附测定法检测母乳中的转化生长因子（TGF）β1、TGFβ2和IL-10，同时使用16S rRNA测序对新生儿肠道微生物群进行分析。
单独来看，免疫调节剂TGFβ1和TGFβ2与新生儿肠道微生物组成显著相关（R分别为0.024，P = 0.041；R为0.026，P = 0.012），并增加了丰富度、均匀度和多样性，但IL-10并非如此。然而，TGFβ1和TGFβ2的作用并非相互独立，且TGFβ2的作用强于TGFβ1。较高水平的TGFβ2与几种细菌的相对丰度增加有关，包括链球菌科和瘤胃球菌科的成员，以及葡萄球菌科不同分类群的相对丰度降低。
母乳中TGFβ的浓度解释了母乳喂养新生儿肠道细菌微生物群组成中部分变异性。TGFβ是单独作用还是与其他生物活性成分共同作用以改变细菌组成，需要进一步研究。这些发现有助于加深对母乳喂养如何影响早期生命中肠道微生物群以及潜在免疫发育的理解。
