Gestational age drives development of the preterm cutaneous microbiome in the neonatal period. human skin metagenome

Development of the skin microbiome in preterm infants in the first 4 weeks of life has not been evaluated. We hypothesized that microbial abundance and diversity of the skin microbiota is a function of gestational age and influenced by clinical variables relevant to the preterm neonate, and compared the skin microbiome between preterm and term infants in the first 4 weeks of life and investigated its determinants in this vulnerable period of life. The microbiome community membership and relative abundance were evaluated by amplification and sequencing the bacterial V3-V5 region of the16S rRNA gene on the 454 GS FLX platform. Therichness, diversity and composition of skin microbial communities increased in direct relationship with gestational age in the first 4 weeks of life. Gestational age-dependent development of the cutaneous microbiome is further influenced by intravenous antibiotic exposure, which decreased community abundance and diversity of bacterial communities. In the preterm neonate, the most abundant phylum was Firmicutes (~ 50%) and the most abundant genus was Staphylococcus. Antibiotic exposure increased abundance of Firmicutes and decreased abundance of Bacteroidetes with increasing duration of exposure. Gestational age, which influences maturity of skin structure and function and determines the environment (neonatal intensive care unit), is the major determinant of the development of the preterm cutaneous microbiome.

目前尚未有研究对早产婴儿出生后前4周内的皮肤微生物组（skin microbiome）发育情况进行评估。本研究提出假设：皮肤微生物群的丰度与多样性随胎龄变化，且受早产新生儿相关临床变量影响；据此我们对比了出生后前4周内早产与足月婴儿的皮肤微生物组，并探究了这一生命脆弱阶段中微生物组的影响因素。本研究通过在454 GS FLX平台上扩增并测序细菌16S核糖体RNA（16S rRNA）基因的V3-V5区域，对微生物群落组成与相对丰度进行了分析。在出生后的前4周内，皮肤微生物群落的丰富度、多样性及组成均随胎龄增长而提升。皮肤微生物组的胎龄依赖性发育还会受到静脉抗生素暴露的影响：抗生素暴露会降低细菌群落的丰度与多样性。在早产新生儿中，占比最高的菌门为厚壁菌门（Firmicutes，约占50%），占比最高的菌属为葡萄球菌属（Staphylococcus）。随着抗生素暴露时长增加，厚壁菌门的丰度会上升，而拟杆菌门（Bacteroidetes）的丰度则会下降。胎龄作为影响皮肤结构与功能成熟度、并决定新生儿所处环境（新生儿重症监护病房，NICU）的关键因素，是早产婴儿皮肤微生物组发育的主要决定因素。