Adolescent Dietary Supplementation of Omega‐3 Polyunsaturated Fatty Acids Alleviates PTSD‐Like Fear Memory and Affective Dysregulation in Rats

ABSTRACT

Post‐traumatic stress disorder (PTSD) is a debilitating psychiatric disorder affecting approximately 3.9% of individuals worldwide over their lifetimes. Since adolescence is characterized by ongoing brain maturation and increased responsiveness to environmental stressors, this developmental stage may provide an important window for PTSD intervention. Growing evidence supports an association between ω‐3 polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), and the restoration of stress‐induced neural damage. However, how ω‐3 PUFA supplementation during adolescence affects adult susceptibility to PTSD remains poorly understood. Here, we observed significantly reduced DHA and EPA concentrations in the prefrontal cortex (PFC) and serum of PTSD‐susceptible rats. Providing 1.2% DHA and EPA in the adolescent diet significantly reduced PTSD‐like phenotypes in adulthood, including excessive fear memory retention, depressive‐like and anxiety‐like behaviors, while also reducing serum levels of proinflammatory cytokines. These phenotypic and inflammatory improvements were associated with changes in the gut microbiome, including its composition and diversity. DHA/EPA supplementation was also linked to alterations in multiple lipid species, with serum phosphatidylcholine levels showing a significant correlation with fear memory expression. Moreover, we observed dysregulation of the PI3K/AKT/mTOR pathway in the PFC of PTSD‐like rats, which was less pronounced in DHA/EPA‐supplemented animals. Collectively, these findings provide the first evidence relating adolescent ω‐3 PUFA status to PTSD‐like phenotypes in adulthood. It further identifies that gut microbiota composition, lipid metabolic profiles (notably phosphatidylcholine), and prefrontal PI3K/AKT/mTOR signaling are correlated with these behavioral outcomes, suggesting that these systems may collectively contribute to trauma resilience.