Appropriate development of the intestinal microbiota during infancy is known to be important for human health. In fact, aberrant alterations of the microbial composition during childhood may cause short- and/or long-term negative health effects. Many factors influence the initial assembly and subsequent progression of the gut microbiota of a neonate, such as feeding type, delivery mode, gestational age, maternal metabolic status and antibiotic exposure.

In the current study, the composition of the infant gut core-microbiota was explored, revealing particular variations of this core-microbiota during the first three years as influenced by delivery mode and feeding type. A multi-population cohort meta-analysis was performed by selecting 15 publicly available datasets pertaining to taxonomic profiles of 1035 fecal samples of healthy infants, as obtained by means of a 16S rRNA gene-based profiling approach. Interestingly, this multi-population cohort meta-analysis revealed great microbial complexity and specific taxonomic shifts in children older than six months, suggesting a major impact by the introduction of solid foods which prompts progression of infant gut microbiota towards that typical of adults. The taxonomic data sets employed in this multi-population cohort meta-analysis possess the statistical robustness to allow the identification of infant community state types (ICSTs). Our analysis therefore reveals the existence of specific taxonomic patterns that correspond to particular nutritional and developmental stages of early life, and that had previously been obscured by the high variability typical of such infant gut microbiota.

众所周知，婴儿期肠道菌群的适当发育对人体健康很重要。实际上，儿童时期微生物组成的异常改变可能会导致短期和/或长期的负面健康影响。许多因素会影响新生儿肠道菌群的初始组装和后续进程，例如进食类型，分娩方式，胎龄，孕产妇代谢状况和抗生素暴露。

在当前的研究中，探索了婴儿肠道核心菌群的组成，揭示了在最初的三年中该核心菌群受分娩方式和喂养方式的特殊变化。通过选择与1035例健康婴儿粪便样品分类学档案有关的15个公开可用数据集，进行了多人群队列荟萃分析，该数据集是通过基于16S rRNA基因的分析方法获得的。有趣的是，这项多族群荟萃分析显示，六个月以上的儿童存在极大的微生物复杂性和特定的分类学变化，这表明固体食物的引入会产生重大影响，促使婴儿肠道菌群发展为成年人。在这项多族群荟萃分析中采用的分类学数据集具有统计稳健性，可以识别婴儿社区状态类型（ICST）。因此，我们的分析揭示了特定分类学模式的存在，这些模式与早期生命的特定营养和发育阶段相对应，并且以前已被此类婴儿肠道菌群典型的高变异性所掩盖。