PURPOSE OF REVIEW: To provide an update of recent studies exploring the role of the gut microbiota and diet in the pathogenesis and treatment of irritable bowel syndrome (IBS). RECENT FINDINGS: The human gut microbiome has been recognized as an important, active source of signaling molecules that explain in part the disorder of the gut brain interaction (DGBI) in IBS. Subsequent changes in the metabolome such as the production of short-chain fatty acids (SCFA) and serotonin are associated with IBS symptoms. Dietary components are recognized as important triggers of IBS symptoms and a diet low in fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs) has been shown effective and safe, even when used long-term. Fecal microbiota transplantation (FMT) in IBS has not shown sustained and effective IBS symptom reduction in controlled clinical trials. SUMMARY: This update elucidates recent developments in IBS as it relates to clinical trial results targeting dietary and gut microbiota interventions. The gut microbiome is metabolically active and affects the bi-directional signaling of the gut-brain axis.