Interleukin-6 in irritable bowel syndrome: A systematic review and meta-analysis of IL-6 (-G174C) and circulating IL-6 levels

The higher IL-6 levels in IBS and more specifically in IBS-D suggests a pro-inflammatory phenotype in these patients, while this phenomenon is not supported by the polymorphism of IL-6 (-G174C). Increased IL-6 in IBS might be an acquired phenomenon or mediated by other genotypes. Any potential association between gene polymorphisms and IL-6 levels in IBS should be tested by assessing both IL-6 levels and IL-6 (-G174C) simultaneously in the same IBS subjects compared to their healthy controls. Categorizing patients based on their circulating IL-6 levels may introduce a new opportunity for personalized anti-inflammatory therapies of IBS.