The role of short-chain fatty acids and neuroinflammation in PTSD pathogenesis: A gut microbial perspective

Exposure to severe psychological trauma is a recognized etiological precursor to post-traumatic stress disorder (PTSD), a potentially debilitating psychiatric condition. Increasing evidence indicates a strong connection between mental disorders and the metabolic system, in which the gut microbiota, as a key component, exerts significant influence on psychiatric health. The gut is often referred to as the "second brain", the gut engages in bidirectional communication with the central nervous system to maintain physiological homeostasis. Trauma affecting the nervous system and cognitive functions such as learning and memory can disrupt the gut microbial community and even trigger inflammatory responses. Conversely, changes in the gut microbiota can adversely affect neurocognitive function. This review systematically summarizes the bidirectional relationship between PTSD and gut microbiota, the pathways through which microbial dysbiosis influences PTSD symptoms, and the underlying mechanisms involving immune regulation, microbial metabolites, and vagus nerve signaling. It also discusses microbiota-based intervention strategies for PTSD, aiming to provide a theoretical foundation for microbial-targeted therapeutic approaches.