中文摘要：

母乳是婴儿最健康、理想的营养来源，也是人类进化和文明最重要的特征之一．最新的宏基因组学研究表明母乳含有高达数百种细菌，而且包括一些常见的病原菌．母乳微生物菌群是人类与微生物协同进化相互适应的产物，而“微生物群落一宿主”生态系统的动态平衡则应是保持健康母乳的基础．然而，迄今为止，从生态学角度对母乳微生物菌群的研究近乎空白．本文应用宏观生态学中的“中性”理论和Taylor幂法则分析探讨了母乳菌群群落多样性的进化和维持机制、细菌种间相互作用的机制以及由此产生的细菌种群分布格局．两项理论模型分析交叉验证了母乳微生物群落分布的异质性和非随机性特征，预示了群落中物种间存在一定程度的生态位分化以及占主导作用的优势物种．

英文摘要：

Human milk is considered the most ideal source of nutrition for infants and it plays a critical role in the evolution and civilizations of humans. Unlike our intuitive perception, human milk contains a large number of bacterial species, including some opportunistic pathogens of humans. This phenomenon comes as no surprise to scientists and physicians. Indeed, the existence of milk microbiome is considered to be the result of co-evolutionary and co-adaptive interactions between the microbiome and human host. Furthermore, the dynamic balance in human milk microbiome ecosystem could be fundamental for suppressing the opportunistic pathogens in the breast milk. Nevertheless, there has been little study on milk microbiome from ecological perspectives. In this article, the neutral theory and Taylor＇s power law from macro ecology were applied to investigate the mechanisms of community assembly and species diversity maintenance, as well as the population and species abundance distribution patterns in human milk bacterial communities. Our study reveals the nonrandom and heterogeneous nature of both population abundance and species abundance distributions in milk bacterial communities. Furthermore, all milk bacterial communities failed to fit to the neutral community model, indicating the possibility of niche differentiation and the presence of dominant species.