A total of 24 studies were conducted comparing the gut microbiomes of Irritable Bowel Syndrome (IBS) patients and healthy individuals. Findings showed increased levels of Enterobacteriaceae, Lactobacillaceae, and Bacteroides, while Faecalibacterium, Bifidobacterium, and specific Clostridiales were decreased in IBS patients. Microbiota diversity was lower or similar in IBS cases. However, over 40% of studies lacked details on comparability between cases and controls. These identified bacteria warrant further investigation to discern if they contribute to or result from IBS pathogenesis.