Summary: A child’s developmental path isn’t just written in their DNA; it’s shaped by a complex “conversation” between their birth-day biology and their first-year gut health. A major study reveals that epigenetic switches (DNA methylation) present at birth influence how a baby’s microbiome develops.
Most importantly, the research found that while certain epigenetic patterns increase the risk for Autism (ASD) and ADHD, specific “good” bacteria—like Lachnospira—can step in during the first year of life to mitigate those risks and protect brain health.
Key Facts
- The Epigenetic Map: Researchers analyzed umbilical cord blood from 571 infants to map DNA methylation—molecular tags that turn genes on or off without changing the DNA sequence itself.
- Microbiome Influence: The study tracked the gut bacteria of nearly 1,000 infants at 2, 6, and 12 months. They found that a baby’s “epigenetic setting” at birth actually dictates how diverse their gut microbiome will become by age one.
- The Protection Buffer: Infants with genetic markers linked to ASD or ADHD were less likely to show actual symptoms at age three if they had high levels of Lachnospira pectinoschiza (for ASD) or Parabacteroides distasonis (for ADHD).
- Birth Mode Impact: C-section births were associated with distinct epigenetic changes in genes involved in immune response and brain development, which in turn altered the early gut environment.
- A Window for Intervention: Because the microbiome is “plastic” (changeable) during the first year, the findings suggest that personalized probiotics or diet could eventually be used as “live biotherapeutics” to steer children away from neurodevelopmental challenges.
Source: Cell Press
The gut microbiome and epigenetics—molecular switches that turn genes on or off—are intertwined, and both contribute to neurodevelopment, finds a study publishing April 10 in the Cell Press journal Cell Press Blue.
The researchers showed that epigenetic changes present at birth can impact how an infant’s gut microbiome develops during their first year.
They also identified specific epigenetic changes and gut microbes that were associated with signs of autism spectrum disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) when the children were three years old.
“Certain bacteria seem to offer protection, which is exciting because it suggests there could be ways to support a child’s development through diet or probiotics in the future,” says senior author and gastroenterologist Francis Ka Leung Chan of The Chinese University of Hong Kong.
The first years of life are critical for brain development and immune system maturation. Though previous studies have shown that both early epigenetic changes and gut microbiome development can impact health in later life, little is known about how these two systems interact.
“We wanted to see how the epigenome and microbiome interact in early life and if their interaction could influence a child’s risk of developing neurodevelopmental conditions like ASD and ADHD,” says co-senior author and public health researcher Hein Min Tun of The Chinese University of Hong Kong.
“We discovered a kind of conversation happening: a baby’s epigenetic setting at birth can influence their risk for neurodevelopmental disorders, but the presence of certain ‘good’ bacteria in their gut can step in and modify the risk.”
The researchers characterized DNA methylation patterns—a type of epigenetic change—from the umbilical cord blood of 571 infants. They paired this information with gut microbiome data collected from 969 infants at 2, 6, and 12 months of age, and from their parents during the third trimester of pregnancy.
When the children reached 36 months of age, the researchers used a behavioral questionnaire to assess their neurodevelopment and investigate links between the microbiome, epigenome, and early signs of ASD and ADHD.
They found that an infant’s epigenome at birth was associated with birth mode, length of gestation, having older siblings, and maternal allergies, but it was not affected by their parents’ gut microbiomes. Microbiome development, on the other hand, was associated with birth mode, antibiotics, having older siblings, and breastfeeding.
Infants who were born by Caesarean section showed different patterns of DNA methylation for several genes involved in immune responses and brain development.
The team also showed that an infant’s epigenome at birth impacted how their microbiome developed during their first year. Specifically, infants developed less diverse gut microbiomes at 12 months of age when they showed higher rates of DNA methylation in immune genes involved in recognizing pathogens.
The behavioral survey revealed that signs of ASD and ADHD in 3-year-olds were associated with specific epigenetic patterns and the presence of certain gut microbes. However, other microbial species seemed to mitigate these effects: infants with epigenetic patterns associated with ASD or ADHD were less likely to show signs of the disorders if they acquired Lachnospira pectinoschiza and Parabacteroides distasonis, respectively, during their first year.
“The foundations for brain health are laid very early, even before birth,” says Tun. “However, we don’t want people to think this means a child’s developmental path is fixed at birth. These are complex conditions with many causes, and we’ve only uncovered a small piece of a very large puzzle.”
The researchers are continuing to follow the children who participated in the study to see how these early-life factors relate to their health as they grow. They note that laboratory experiments are needed to confirm the associations between gut microbes and neurodevelopment.
“The ultimate goal is to develop safe, non-intrusive early interventions such as specific probiotics or live biotherapeutics, that could help nurture a healthy gut microbiome and potentially reduce the risk of neurodevelopmental challenges,” says first author and gastroenterologist Siew Chien Ng of The Chinese University of Hong Kong.
Funding:
This research was supported by funding from InnoHK, the Government of Hong Kong, the D. H. Chen Foundation and the New Cornerstone Science Foundation.
Key Questions Answered:
A: Absolutely not. The study’s most exciting finding is that the “path” isn’t fixed. The microbiome acts as a secondary control system. If a child acquires specific protective bacteria during their first 12 months, those microbes can essentially “override” or soften the impact of the epigenetic risk markers.
A: Birth mode is a massive biological event. The researchers found that C-sections are linked to different DNA methylation patterns in immune and brain-development genes. This doesn’t mean C-sections cause disorders, but they do set up a different “starting point” for how the immune system and gut bacteria begin to interact.
A: Not yet. While the association is strong, we are still in the “puzzle-solving” phase. Scientists need to conduct clinical trials to prove that adding these specific bacteria can safely change neurodevelopmental outcomes. For now, the best way to support a healthy microbiome is through established methods like breastfeeding and avoiding unnecessary antibiotics.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- Journal paper reviewed in full.
- Additional context added by our staff.
About this microbiome and autism research news
Author: Julia Grimmett
Source: Cell Press
Contact: Julia Grimmett – Cell Press
Image: The image is credited to Neuroscience News
Original Research: Closed access.
“Epigenome-microbiome interplay in early life associates with infants’ neurodevelopmental outcomes” by Siew Chien Ng, Ye Peng, Lin Zhang, Shilin Zhao, Oscar Wong, Xin Liu, Hang Li, Jie Zhu, Yingzhi Liu, Qi Su, Wing Hung Tam, Tak Yeung Leung, Sandra Chan, Patrick Leung, Jessica Yuet-Ling Ching, Pui-Kuan Cheong, Long Ip, Amy Mei Kam Chang, Xi Zhang, Xueqi Wu, Yuzhou Chen, Shuai Yan, Whitney Tang, Chun Pun Cheung, Ting Fan Leung, Hein Min Tun, and Francis Ka Leung Chan. 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 sensitive to perinatal cues. We studied early-life disruptions in the host epigenome and microbial colonization in relation to neurodevelopmental disorders.
In a longitudinal birth cohort, we analyzed 571 cord blood methylomes and 5,328 gut metagenomes from infants and their parents across 969 families to unravel microbiome-epigenome interactions in neuro-immune pathways.
We found that Caesarean-section delivery was associated with differential methylation of genes involved in immune responses and neural development. It also reduced vertical maternal microbiome transmission, partially compensated by the paternal microbiome.
Children with hypermethylated genes involved in neurogenic and neurotransmission pathways in cord blood showed higher autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) scores at age 3.
However, these epigenetic effects were mitigated by early colonization of Lachnospira pectinoschiza in ASD and Parabacteroides distasonis in ADHD.
These findings highlight early-life epigenetic regulation and microbiome-dependent mechanisms in the developmental origins of neurodevelopmental disorders.
