Bacteria colonisation of the foal’s gastrointestinal tract (GIT) is a critical developmental stage, effecting subsequent immunological and health outcomes. It has long been thought that the equine fetus develops in a sterile intrauterine environment and GIT colonisation commences at birth. Research now suggests that bacteria isolated from amniotic fluid are the initial colonisers of the fetal GIT, and exposure to the dam’s microbiota and the external environment during birth provide supplementary colonisation. This in utero colonisation hypothesis has only recently been examined in the horse and microbiota were detected in the amniotic fluid and meconium of healthy equine pregnancies. This review highlights the possible colonisation routes of these bacteria into the fetal compartments and examines their likely origins from the existing maternal microbiome. However, the current data describing the amniotic microbiota of the horse are limited and there is a need for research to fill this gap. Understanding the significance of intrauterine microbes for foal GIT colonisation may provide strategies to improve neonatal health.

中文翻译：

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产前建立小马驹肠道微生物群：对子宫内定植假说的批判

小马驹胃肠道 (GIT) 的细菌定植是一个关键的发育阶段，会影响随后的免疫和健康结果。长期以来，人们一直认为马胎儿在无菌的宫内环境中发育，GIT 定植在出生时就开始了。现在的研究表明，从羊水中分离出的细菌是胎儿 GIT 的最初定植者，出生时暴露于母猪的微生物群和外部环境提供了补充定植。这种子宫内定植假说最近才在马身上得到检验，并且在健康马怀孕的羊水和胎粪中检测到微生物群。这篇综述强调了这些细菌在胎儿隔室中可能的定植途径，并检查了它们可能来自现有母体微生物组的来源。然而，目前描述马羊膜微生物群的数据有限，需要进行研究来填补这一空白。了解宫内微生物对小马 GIT 定植的重要性可能会提供改善新生儿健康的策略。