The gut microbiome appears to play an important role in human health and disease. However, only little is known about how variability in the gut microbiome contributes to individual differences during early and sensitive stages of brain and behavioral development. The current study examined the link between gut microbiome, brain, and behavior in newborn infants (N = 63; M [age] = 25 days). Infant gut microbiome diversity was measured from stool samples using metagenomic sequencing, infant functional brain network connectivity was assessed using a resting state functional near infrared spectroscopy (rs-fNIRS) procedure and infant behavioral temperament was assessed using parental report. Our results show that gut microbiota composition is linked to individual variability in brain network connectivity, which in turn mediated individual differences in behavioral temperament, specifically negative emotionality, among infants. Furthermore, virulence factors, possibly indexing pathogenic activity were associated with differences in brain network connectivity linked to negative emotionality. These findings provide novel insights into the early developmental origins of the gut microbiome-brain axis and its association with variability in important behavioral traits. This suggests that the gut microbiome is an important biological factor to consider when studying human development and health.

中文翻译：

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肠道微生物群组成与新生儿功能性大脑连接和行为气质有关

肠道微生物组似乎在人类健康和疾病中发挥着重要作用。然而，在大脑和行为发育的早期和敏感阶段，肠道微生物组的变异性如何导致个体差异，我们知之甚少。目前的研究检查了新生儿（N = 63；M [年龄] = 25 天）的肠道微生物组、大脑和行为之间的联系。使用宏基因组测序从粪便样本中测量婴儿肠道微生物组的多样性，使用静息状态功能近红外光谱 (rs-fNIRS) 程序评估婴儿功能性大脑网络连接，使用父母报告评估婴儿行为气质。我们的结果表明肠道微生物群的组成与大脑网络连接的个体差异有关，这反过来又介导了婴儿行为气质的个体差异，特别是负面情绪。此外，毒力因子，可能是致病活动的索引，与与负面情绪相关的大脑网络连接的差异有关。这些发现为肠道微生物组-大脑轴的早期发育起源及其与重要行为特征变异性的关联提供了新的见解。这表明肠道微生物组是研究人类发育和健康时需要考虑的重要生物学因素。这些发现为肠道微生物组-大脑轴的早期发育起源及其与重要行为特征变异性的关联提供了新的见解。这表明肠道微生物组是研究人类发育和健康时需要考虑的重要生物学因素。这些发现为肠道微生物组-大脑轴的早期发育起源及其与重要行为特征变异性的关联提供了新的见解。这表明肠道微生物组是研究人类发育和健康时需要考虑的重要生物学因素。