Gut Microbiome and Its Role in the Pathophysiology of Irritable Bowel Syndrome

Irritable bowel syndrome is the most common functional gastrointestinal disorder, affecting up to 9% individuals globally. Although the etiology of this syndrome is likely heterogenous, it presents with its hallmark symptoms of abdominal pain and altered intestinal motility. Moreover, it is considered to be a disorder of the gut-brain interaction, and the microbiome has often been implicated as a central player in its pathophysiology. Patients with irritable bowel syndrome display altered composition and function of the gut microbiota compared to healthy controls. Microbiome directed therapies, such as probiotics, antibiotics and fecal microbiome transplantation, appear to be beneficial for both gut symptoms and psychiatric comorbidities. This review aims to recapitulate the available literature on the microbiome contribution to the pathophysiology and symptoms presentation of irritable bowel syndrome, as well as the current literature on microbiome-targeted treatments for this disease.