Summary: Early development is shaped not only by genetics but also by interactions between newborn epigenetic marks and the emerging gut microbiome during the first year. A large longitudinal study shows that DNA methylation patterns present at birth influence how an infant’s gut bacteria mature, and that certain microbes acquired in infancy can reduce the risk of neurodevelopmental problems linked to those epigenetic signatures.
The research highlights that while some epigenetic profiles increase the likelihood of autism spectrum disorder (ASD) or attention-deficit/hyperactivity disorder (ADHD), colonization by specific beneficial bacteria—such as Lachnospira—during the first year can buffer those risks and support healthy brain development.
Key Facts
- The Epigenetic Map: Scientists profiled DNA methylation in umbilical cord blood from 571 infants, identifying epigenetic marks that can alter gene activity without changing DNA sequence.
- Microbiome Influence: Gut microbiome trajectories were tracked in nearly 1,000 infants at 2, 6, and 12 months. The results show that an infant’s epigenetic state at birth helps determine microbial diversity and composition by age one.
- The Protection Buffer: Infants with epigenetic markers linked to ASD or ADHD were less likely to show symptoms at age three when they had early-life colonization by Lachnospira pectinoschiza (associated with reduced ASD signs) or Parabacteroides distasonis (associated with reduced ADHD signs).
- Birth Mode Impact: Delivery by Caesarean section correlated with distinct methylation shifts in genes tied to immune function and brain development, which in turn influenced early microbial colonization.
- A Window for Intervention: Because the infant microbiome is changeable during the first year, personalized probiotics or dietary strategies could eventually serve as safe, targeted ways to support neurodevelopment and reduce risk.
Source: Cell Press
The gut microbiome and epigenetics—molecular switches that regulate gene expression—are interconnected, and both shape early neurodevelopment, according to a study published April 10 in a Cell Press journal.
The research team demonstrated that epigenetic differences measurable at birth can direct how an infant’s gut microbiome matures over the first 12 months. They also identified specific epigenetic signatures and microbial species that associate with early behavioral signs of ASD and ADHD by age three.
“Finding microbes that appear to offer protection is encouraging because it points to possible noninvasive ways to support early brain development through diet or probiotics,” says senior author Francis Ka Leung Chan, a gastroenterologist at The Chinese University of Hong Kong.
The first years of life are a pivotal period for both immune system maturation and neural development. Although prior studies linked either early epigenetic changes or microbiome patterns with later health, this study focused on how those two systems interact and jointly influence neurodevelopmental outcomes.
“We sought to understand whether the newborn epigenome and the evolving gut microbiome interact in ways that change a child’s risk for conditions like ASD and ADHD,” explains co-senior author Hein Min Tun, a public health researcher at The Chinese University of Hong Kong. “Our results suggest a dynamic dialogue: birth-day epigenetic settings can shape later risk, but early microbial exposures can modify that trajectory.”
The investigators analyzed cord blood methylation profiles from 571 infants and matched those data with gut microbiome samples collected from 969 infants at 2, 6, and 12 months, plus parental samples during late pregnancy. At 36 months, they assessed child behavior with standardized questionnaires to explore links among epigenome, microbiome, and early signs of ASD and ADHD.
Epigenetic patterns at birth correlated with factors such as delivery mode, gestational age, presence of older siblings, and maternal allergy history; these marks did not mirror parental gut microbiomes directly. By contrast, postnatal microbiome development was influenced by delivery mode, antibiotic exposure, sibling interactions, and breastfeeding practices.
Babies delivered by Caesarean section showed different methylation at genes involved in immune signaling and neural development. Higher methylation in certain immune genes at birth predicted lower microbial diversity by 12 months, indicating that the epigenome may help set the ecological rules for microbiome assembly.
Behavioral screening at age three linked specific methylation patterns and some microbial signatures to elevated ASD and ADHD scores. Importantly, the presence of particular gut species during the first year—Lachnospira pectinoschiza for ASD-related patterns and Parabacteroides distasonis for ADHD-related patterns—appeared to attenuate the association between epigenetic risk and observable symptoms.
“These findings reinforce that early-life biology matters, but they also emphasize plasticity,” says Tun. “An epigenetic risk marker at birth does not seal a child’s fate. Microbial exposures and other environmental factors can alter developmental trajectories.”
The research team is following the cohort longitudinally to see how early epigenetic and microbial factors relate to development over time. Laboratory and clinical trials will be necessary to confirm causal links and to test whether safe, targeted live biotherapeutics or probiotic interventions can support healthy neurodevelopment.
“Our long-term aim is to develop noninvasive, evidence-based strategies—such as validated probiotics or dietary approaches—that nurture a healthy infant microbiome and potentially reduce neurodevelopmental risk,” says first author Siew Chien Ng, a gastroenterologist at The Chinese University of Hong Kong.
Funding:
This study received support from InnoHK, the Government of Hong Kong, the D. H. Chen Foundation, and the New Cornerstone Science Foundation.
Key Questions Answered:
A: Not at all. The study suggests that the microbiome acts as a secondary, modifiable layer of influence. Early colonization by certain protective bacteria during the first year can lessen or alter the impact of epigenetic risk markers.
A: Delivery by Caesarean section was associated with different DNA methylation patterns in genes tied to immune function and brain development. This finding indicates a different biological starting point for immune–microbiome interactions, not proof that C-sections cause neurodevelopmental disorders.
A: No. While the associations are promising, clinical trials are needed to confirm safety and efficacy. Currently recommended practices to support a healthy infant microbiome include breastfeeding when possible, cautious use of antibiotics, and following pediatric guidance.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- The full journal paper was reviewed for accuracy.
- Additional context was provided by editorial staff.
About this microbiome and autism research news
Author: Julia Grimmett
Source: Cell Press
Contact: Julia Grimmett – Cell Press
Image: Image credit: Neuroscience News
Original Research: Closed access. “Epigenome-microbiome interplay in early life associates with infants’ neurodevelopmental outcomes” by Siew Chien Ng et al., Cell Press Blue. DOI: 10.1016/j.cpblue.2026.100009
Abstract
Epigenome-microbiome interplay in early life associates with infants’ neurodevelopmental outcomes
Epigenetic regulation and microbiome maturation are highly responsive to perinatal signals. In this longitudinal birth cohort, researchers analyzed 571 cord blood methylomes and 5,328 gut metagenomes from infants and parents across 969 families to examine microbiome–epigenome interactions in neuro-immune pathways. Caesarean delivery associated with differential methylation in genes linked to immune and neural development and altered vertical maternal microbiome transfer. Children with hypermethylation in neurogenic and neurotransmission-related genes showed higher ASD and ADHD scores at age three, but early colonization with Lachnospira pectinoschiza (ASD) and Parabacteroides distasonis (ADHD) mitigated these associations. These results highlight early-life epigenetic programming and microbiome-dependent mechanisms in the developmental origins of neurodevelopmental disorders.