Abstract: Objective　To investigate the influencing factors of early intestinal flora on the occurrence of infant dyschezia by analyzing clinical characteristics and sequencing meconium samples collected within 72h after birth，so as to provide new insights for early intestinal intervention. Methods　Full-term neonates born at Shenzhen Maternity and Child Healthcare Hospital，Southern Medical University between January 2021 and April 2021 were enrolled. Clinical data were collected，and meconium samples were obtained within 72 h after birth. A questionnaire survey was completed by telephone follow-up at 3 months of age，and the infants suspected with dyschezia were recalled for hospital re-evaluation. Those meeting the RomeⅣ criteria were assigned to the infant dyschezia group，and the remaining infants were enrolled as the non-infant dyschezia group using propensity score matching at a ratio of 1︰4. Baseline clinical data were compared between the two groups，and analyze associated factors. In addition，another healthy control group were matched at a ratio of 1︰1 from the remaining cases using propensity score matching. The 16SrDNA sequencing was performed on the meconium samples of the two groups to compare differences in intestinal flora diversity，richness and community structure. Results　The incidence of infant dyschezia was 4.3%. The prophylactic antibiotics use during the neonatal period was significantly different between the infant dyschezia group and the non- infant dyschezia group（P<0.05）. Vaginal delivery and prophylactic antibiotic use during the neonatal period were risk factors for infant dyschezia. There were no significant differences in the diversity and richness of intestinal flora between the infant dyschezia group and the healthy control group（P>0.05）. However，statistically significant differences were found in community structure at the phylum level of Spirochaetes and the genus levels of Bacteroides between the two groups（P<0.05）. Conclusion　Vaginal delivery and prophylactic antibiotic use can increase the risk of developing infant dyschezia. No significant differences exist in the diversity and richness of early intestinal flora between the infants with dyschezia and the healthy infants in the postnatal period，whereas the relative abundance of Bacteroides at the genus level is significant higher than in healthy infants.

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摘要： 目的　通过对婴儿排便困难临床特征及生后72 h内的胎粪测序分析，探讨生后早期肠道菌群对婴儿排便困难发生的影响因素，为早期肠道干预提供新思路。方法　选取2021年1月至4月南方医科大学深圳妇幼保健院出生的足月新生儿，收集研究对象的临床特征并留取生后72 h内胎粪，于3月龄电话随访完善调查问卷，疑似婴儿排便困难的来院复诊。符合罗马Ⅳ诊断标准确诊为排便困难组，采用倾向性评分匹配方法，按1︰4比例在其余健康婴儿中选取非排便困难组，比较两组基本临床资料差异并分析相关因素；另采用倾向性评分匹配方法，按1︰1比例在其余病例中匹配健康对照组，对两组胎粪标本行16S rDNA测序，比较肠道菌群多样性、丰富度及群落结构差异。结果　婴儿排便困难发生率为4.3%。排便困难组与非排便困难组在新生儿期预防性使用抗生素方面差异有统计学意义（P<0.05），阴道分娩、新生儿期预防性使用抗生素是发生婴儿排便困难的危险因素。婴儿排便困难组胎粪肠道菌群多样性及丰富度与健康对照组比较差异无统计学意义（P>0.05）；但在螺旋体门及拟杆菌属水平的群落结构上，两组差异有统计学意义（P<0.05）。结论　阴道分娩及新生儿期预防性使用抗生素可增加婴儿排便困难的发生风险。婴儿排便困难在出生早期肠道菌群多样性及丰度与健康婴儿差异无统计学意义，而在群落结构上拟杆菌属水平显著高于健康婴儿。

关键词: 婴儿排便困难, 肠道菌群, 抗生素, 危险因素, 胎粪, 16SrDNA测序