Perioperative neurocognitive disorders (PND) refer to a constellation of symptoms that primarily affect the elderly and typically manifest as common complications after exposure to surgery and anesthesia. PND is associated with high morbidity, mortality, and progression to neurodegenerative diseases, thus exerting significant financial strains on families as well as the healthcare system. Given that an ageing global population is an inevitable trend and, with the latest advances in the healthcare system, an ever-growing number of elderly people present for surgery and anesthesia, PND is of prominent concern.

The two-way communication between the intestinal flora and the brain, also known as the microbiota-gut-brain axis, plays an important role in central nervous system development, and multiple studies have highlighted the influence exerted by gut microbiome in both health and disease. Pertinent studies have corroborated the fact that anesthesia and surgery disrupt the harmony of the gut ecology, which sets off a cascade of events that initiate neuroinflammation, eventually leading to PND. Probiotics, which are live microorganisms that promote the host's health, have been shown as a viable option to restore or minimise the disruption of gut flora. Evidence exists that probiotics exhibit immunomodulatory and anti-inflammatory benefits. Given the effectiveness of probiotics in reducing neuroinflammation, research has also focused on their impact on the development of PND.

This review aims to compile the data from relevant clinical trials focusing on the influence of probiotics on PND to determine whether the derived findings might be applied for the prevention and treatment of PND.