A team of researchers at Wuhan University conducted an animal study to explore how prenatal exposure to caffeine combined with a high-fat diet might influence autism-related behaviors in offspring. The work was published in the Ecotoxicology and Environmental Safety journal.
The researchers observed that the risk of autism-like traits in rodent offspring appears to be linked with alterations in gut microbial communities and elevated levels of the immune molecule IL-17A, suggesting a gut–immune–brain interaction as part of the observed effects.
In the experimental design, pregnant rats were assigned to two groups: one received caffeine during a critical window of gestation and the other was a control group given a placebo.
Following birth, the pups were further divided based on diet. They were fed either a standard diet or a high-fat diet starting from the fourth week after birth, allowing researchers to assess the interaction between maternal exposure and postnatal nutrition.
Behavioral assessments indicated that male offspring displayed autism-related behaviors when there was prenatal caffeine exposure. Female offspring showed reductions in exploratory activity and impairments in spatial memory, highlighting potential sex-specific effects in this model.
Biological analyses revealed damage to the mucosal lining of the intestine and notable shifts in the gut microbiota, including an increased abundance of Escherichia coli. This microbial shift correlated with the differentiation of colonic Th17 cells and higher levels of IL-17A, linking gut changes to immune responses observed in the study.
Further investigation showed that IL-17A, a cytokine associated with inflammatory processes, could reach the brain and contribute to synaptic alterations in hippocampal neurons. Such synaptic changes are considered a factor in the development of autism-like outcomes in animal models, according to the researchers.
Previous work in the field has linked certain drugs with elevated risks of autism-related outcomes in newborns, underscoring the importance of understanding how prenatal exposures may influence neurodevelopment and later behavior.