Early-life diets impact brain health, but prebiotics and probiotics may offer solutions

Following a diet high in fat and sugar from an early age can change how the brain regulates eating, according to a new study on mice. It found that even if starting a healthy diet later in life or losing weight, the regulation of eating remains the same. 

The study suggests that frequent consumption of energy-dense, nutrient-poor foods high in sugar and fat shapes children’s food preferences and eating patterns in adulthood. The changes were linked to disruptions in the hypothalamus, a key brain region that is involved in appetite control and energy balance.

“Our findings show that what we eat early in life really matters,” says Dr. Cristina Cuesta-Martí, first author of the study. “Early dietary exposure may leave hidden, long-term effects on feeding behavior that are not immediately visible through weight alone.”

However, probiotics and prebiotics showed potential to restore these negative impacts. The study found that targeting the gut microbiota with the bacterial strain Bifidobacterium longum APC1472 and the prebiotic combination FOS+GOS (fructooligosaccharides and galactooligosaccharides) could counteract these long-term diet-related effects.

Disturbing pathways

The study, published in Nature Communications, was conducted on mice and found that unhealthy diets early in life disrupted brain pathways involved in eating behavior. There were also sex-specific differences in the results.

The mice were fed a high-fat, high-sugar diet from birth to five weeks of age. The researchers tested feeding behavior and weight gain at 10–11 weeks of age. At 12 weeks of age, they tested blood and metabolites, hypothalamic gene expression, and neuron studies.

“Studies like this exemplify how fundamental research can lead to potential innovative solutions for major societal challenges. By revealing how early-life diet shapes brain pathways involved in the regulation of feeding, this work opens new opportunities for microbiota-based interventions,” comments professor John Cryan, VP for Research & Innovation at University College Cork, Ireland, and collaborator on the study.

The female mice were more affected by the unhealthy diets, with more changes in brain areas that control eating, compared to males. However, male mice experienced more metabolic issues.

The researchers found that an unhealthy diet had long-lasting effects on the mice’s metabolism and the body’s processing of fats, sugars, and certain amino acids.

The study found that unhealthy diets early in life disrupted brain pathways involved in eating behavior.Pro and prebiotics

The probiotic strain B. longum APC1472 showed potential to improve eating behaviors and brain function. It showed to work best for females, with fewer changes in gut bacteria.

The researchers also investigated prebiotic FOS and GOS, which they found helped restore gut bacteria in both females and males.

Dr. Harriet Schellekens, lead investigator of the study, comments: “Crucially, our findings show that targeting the gut microbiota can mitigate the long-term effects of an unhealthy early-life diet on later feeding behavior. Supporting the gut microbiota from birth helps maintain healthier food-related behaviors into later life.”

In line with the new findings, another recent Icelandic study found that following the national nutritional guidelines for infants — exclusive breastfeeding, then transitioning to a healthy diet of solid foods, and vitamin D supplementation — may lower the risk of overweight and obesity later in childhood.

Globally, children are growing up in food environments filled with high levels of saturated fat and sugar. UNICEF recently marked 2025 as a “historical turning point,” as child obesity overtook child undernutrition on a global scale.