Scientists discover gut bacteria that may help protect against autism and ADHD
A new study reveals that epigenetic changes at birth influence the gut microbiome, and certain bacteria may reduce the risk of neurodevelopmental disorders.
Scientists from The Chinese University of Hong Kong have uncovered a surprising connection between a baby's earliest biological programming, the gut microbiome, and later brain development. The findings, published in Cell Press Blue, suggest that epigenetic changes present at birth can influence how gut bacteria develop during infancy. The study also found links between specific epigenetic patterns, certain gut microbes, and signs of autism spectrum disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) by age three.
The research team analyzed DNA methylation patterns, a common form of epigenetic modification, in umbilical cord blood from 571 infants. They combined those data with gut microbiome samples collected from 969 infants at 2, 6, and 12 months of age, along with microbiome samples from the infants' parents during the third trimester of pregnancy. When the children reached 36 months of age, researchers assessed their neurodevelopment using a behavioral questionnaire and looked for connections between developmental outcomes, gut microbes, and epigenetic patterns.
The researchers found that several factors were associated with epigenetic patterns at birth, including delivery method, length of pregnancy, having older siblings, and maternal allergies. Interestingly, parental gut microbiomes did not appear to influence these birth-related epigenetic changes. The development of the infant microbiome was linked to a different set of factors: delivery method, antibiotic exposure, older siblings, and breastfeeding all played a role.
The study also revealed that epigenetic patterns present at birth affected how the gut microbiome evolved during infancy. Infants who had higher levels of DNA methylation in certain immune-related genes tended to develop less diverse gut microbiomes by 12 months of age. These genes are involved in helping the body recognize and respond to pathogens.
When researchers examined behavioral outcomes at age three, they found that signs of ASD and ADHD were associated with specific combinations of epigenetic markers and gut microbes. However, the findings also pointed to a potentially protective role for certain bacteria. Children who carried epigenetic patterns associated with ASD were less likely to show signs of the condition if they acquired Lachnospira pectinoschiza during infancy. Similarly, children with epigenetic patterns associated with ADHD appeared less likely to show signs of the disorder if they acquired Parabacteroides distasonis during their first year.
The researchers are continuing to follow the participating children to better understand how early-life epigenetic patterns and microbiome development influence health later in childhood. They emphasize that laboratory studies will be needed to confirm the observed relationships between gut bacteria and neurodevelopment. The ultimate goal is to develop safe, non-intrusive early interventions such as specific probiotics or live biotherapeutics that could potentially reduce the risk of neurodevelopmental challenges.
