Gut-brain axis and post-operative cognitive dysfunction: A multifactorial perspective on microbiota, inflammation, and cognitive health

Abstract

Post-operative cognitive dysfunction (POCD) is a common but often overlooked issue, especially in older adults after surgery. This review looks into how the gut and brain are connected—a relationship known as the gut-brain axis—and how tiny microbes living in our gut might influence our brain health during recovery. The gut microbiota helps produce important substances like short-chain fatty acids and neurotransmitters that play a key role in memory, mood, and brain function. Among these microbes, Akkermansia muciniphila stands out for supporting the gut lining, reducing inflammation, and balancing chemicals that affect cognition. Surgery, anesthesia, and antibiotics can disturb this balance, leading to “gut dysbiosis”, which may trigger brain inflammation and worsen POCD. By reviewing 11 carefully selected studies, this paper explores how restoring gut health—using probiotics like Akkermansia muciniphila or combinations like VSL#3—could be a promising way to protect the brain after surgery. Overall, these findings highlight a powerful connection between gut health and brain recovery, suggesting that personalized probiotic treatments might one day help improve mental outcomes in surgical patients. More clinical studies are needed, but the potential here is both exciting and hopeful.

Keywords: Gut-brain axis; Post-operative cognitive dysfunction; Gut microbiota; Akkermansia muciniphila; Neuroinflammation; Short-chain fatty acids; Gut dysbiosis; Cognitive outcomes after surgery; Probiotic intervention; Microbiota-based targeted therapy

Core Tip: This review explores the important connection between gut health and brain function, especially in patients recovering from surgery. It focuses on how disturbances in gut microbes after surgery can lead to inflammation, impaired gut barrier function, and memory issues—collectively known as post-operative cognitive dysfunction. The article highlights growing evidence that restoring gut balance using probiotics and other microbiota-based therapies may help reduce inflammation and support better cognitive recovery. By drawing attention to the gut-brain link, this review opens up new possibilities for non-invasive strategies to protect the brain and improve mental clarity in post-surgical patients.