Scientists have discovered a surprising link between a baby’s earliest biological programming, the gut microbiome, and later brain development. The survey results are Cell Press Bluesuggesting that epigenetic changes present at birth can influence the development of gut microbiota during early childhood. The study also found an association between specific epigenetic patterns, specific gut microbes, and symptoms of autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD) by age 3.
“This is interesting because certain bacteria seem to offer protection, suggesting that in the future there may be ways to support child development through diet and probiotics,” says lead author and gastroenterologist Francis Ka Leung Chan from the Chinese University of Hong Kong.
How early biology shapes development
The first years of life are critical for both brain development and immune system maturation. Previous research has shown that epigenetics and the gut microbiome can each influence long-term health, but scientists have limited understanding of how these two systems interact during early childhood.
“We wanted to know how the epigenome and microbiome interact during early childhood, and whether those interactions may influence a child’s risk of developing neurodevelopmental diseases such as ASD and ADHD,” says co-author and public health researcher Hein Min Tung from the Chinese University of Hong Kong. “We discovered that there is a kind of conversation going on: a baby’s epigenetic environment at birth can influence the risk of neurodevelopmental disorders, but the presence of certain ‘good’ bacteria in the gut can intervene and alter the risk.”
To investigate, the research team analyzed DNA methylation patterns, a common form of epigenetic modification, in the umbilical cord blood of 571 infants. They combined these data with gut microbiome samples collected from 969 infants at ages 2, 6, and 12 months, as well as microbiome samples taken from the infants’ parents during late pregnancy.
When the children reached 36 months of age, the researchers used behavioral questionnaires to assess their neurodevelopment and looked for connections between developmental outcomes, gut bacteria, and epigenetic patterns.
Factors influencing the infant’s microbiome
Researchers found that several factors were associated with epigenetic patterns at birth, including birth method, gestational age, presence of older siblings, and maternal allergies. Interestingly, the parental gut microbiota does not seem to influence these birth-related epigenetic changes.
Infant microbiome development was associated with a variety of factors. Method of delivery, exposure to antibiotics, older siblings, and breastfeeding all played a role in shaping the microbial community that developed during the first year of life.
Babies delivered by caesarean section showed different DNA methylation patterns in several genes involved in immune function and brain development.
Relationship between gene regulation and intestinal bacteria
The study also revealed that epigenetic patterns present at birth influence the evolution of the gut microbiome during early childhood.
Infants with higher levels of DNA methylation of certain immune-related genes tended to have reduced gut microbiota diversity by 12 months of age. These genes are involved in helping the body recognize and respond to pathogens.
This result suggests that biological signals present at birth may help guide the development of the gut microbial community during the child’s first year of life.
Gut microbes and neurodevelopmental risks
When researchers looked at behavioral outcomes at age 3, they found that signs of ASD and ADHD were associated with a specific combination of epigenetic markers and gut microbes.
However, the discovery also pointed to a potential protective role against certain bacteria. Children with epigenetic patterns associated with ASD were less likely to exhibit ASD symptoms if they acquired it. Lachnospira pectinociza In early childhood. Similarly, children with epigenetic patterns associated with ADHD appear to be less likely to show signs of the disorder if they acquire ADHD. Parabacteroides distasonis In the first year.
“The foundations of brain health are laid very early, even before birth,” says Tan. “But we don’t want people to think that this means that a child’s developmental path is determined at birth. These are complex conditions with many causes, and we are only uncovering a small piece of a very large puzzle.”
Probiotics and the future potential of brain health
Researchers are continuing to follow the participating children to better understand how epigenetic patterns and microbiome development during early childhood influence health later in life. They stress that laboratory studies are needed to confirm the observed relationship between gut bacteria and neurodevelopment.
“The ultimate goal is to develop safe, non-invasive early interventions, such as specific probiotics or biologic therapies, that may foster a healthy gut microbiome and reduce the risk of neurodevelopmental disorders,” says lead author Siew Chien Ng, a gastroenterologist at the Chinese University of Hong Kong.
This research was supported by InnoHK, the Hong Kong government, the DH Chen Foundation, and the New Cornerstone Science Foundation.
