Written by Alison Proffitt
May 7, 2026 | New paper published in Nutrients Summarizes the interconnected development of brain, gut, and sleep in the first 1,000 days of life—from conception to the second birthday. The review highlights a growing body of research linking maternal nutrition and health status during pregnancy directly to infant development, underscoring the need for better support for women before, during and after pregnancy.
Peer-reviewed paper (doi: 10.3390/nu18030445), written by authors associated with SmartyPants Vitamins, University of Arizona, Icahn School of Medicine at Mount Sinai, reviews the literature on nutrients important for brain and gut development in the first 1,000 days of life and links this development to infant sleep. The authors point out gaps in our understanding of this window and highlight how we can better understand how nutritional interventions early in life can improve neurodevelopmental outcomes.
“Parents often hear that the first 1,000 days are important, but this research helps explain why,” says Devyani Chaturvedi, chief nutritional scientist at SmartyPants Vitamins and first author of this paper. “This review helps explain why nutrition not only affects one aspect of development, but simultaneously affects brain development, gut microbiome development, and sleep architecture. These systems interact on an ongoing basis to shape lifelong health.”
Sleep visions
The researchers found that early development does not occur in silos: the brain, gut and sleep develop as interconnected systems, with sleep being an active biological process that interacts with brain development and gut health, rather than just an outcome. Sleep helps shape cognitive, linguistic and behavioral development early in life and is important for both pregnant mothers and their infants.
Pregnancy increases the body’s need for sleep, but common pregnancy-related discomforts and sleep disorders can make those extra hours difficult to achieve. The effects of sleep loss are systemic.
“Lack of sleep leads to dysregulation of the hypothalamic-pituitary-adrenal axis, leading to elevated cortisol while reducing melatonin, which is essential for regulating reproductive hormones and neurodevelopmental signaling. These neuroendocrine and microbial changes disrupt metabolic hormones such as ghrelin and leptin, impairing appetite control and insulin sensitivity, and collectively increasing the risk of adverse pregnancy outcomes.”
In children, sleep appears to be influenced by and influence the gut microbiome. “Perturbations in early microbial development have been associated with changes in sleep-wake cycles, circadian rhythm uniformity, and behavioral outcomes,” the researchers wrote. “Given the importance of sleep and gut health during the early days, understanding the interaction between them may provide new insights into strategies to improve neurodevelopmental outcomes through interventions targeting the microbiome.”
Brain development
The first 1,000 days are a well-known window of explosive brain development. During this time, the brain shows remarkable plasticity, allowing significant modification and improvement of synaptic connections. Different mechanisms can shape neurodevelopment and ultimately neurodevelopmental outcomes, and we know that nutrition influences these outcomes, especially folic acid.
Gut health
The gut microbiome in infants develops rapidly during the first two years of life and plays a key role in neural signaling, immune system development, and sleep regulation, linking nutrition to both brain function and sleep patterns. It is influenced by everything from the mother’s diet to mode of delivery to nutrition and antibiotic use in the first 2 years after birth, and the influence of the gut microbiome on the nervous system (both central and enteric) has been demonstrated in numerous rodent studies.
feeding
The authors argue that nutrition during the first 1,000 days of life is the easiest way to influence the development of these interconnected systems.
The authors assert that “by treating nutrition as a shared resource for brain, gut, and sleep development, there are significant gains to be made in improving child health that may even extend into adulthood.” There is strong evidence on certain nutrients and early life outcomes, such as DHA, choline, and others. But the authors call for more research, including standardized recommendations for nutrients such as omega-3 after six months of age and for biomarkers for early detection of deficiencies in choline and vitamin B12.
“Understanding the science behind early development helps us better support families and healthcare providers,” Chaturvedi added in the same press release. “Investing in this research allows us to contribute to a deeper understanding of maternal health and early life, ensuring our approach remains evidence-based and clinically relevant.”
