Therefore, in the current study, we investigated biomarkers of OS, serum levels of the anti‐inflammatory interleukins IL‐10 and IL‐4, and the pro‐inflammatory TNF‐α and IL‐6, as well as the mediators of the redox homeostasis NF‐κB and Nrf2, as well as the catalytic subunit gp91phox of NADPH oxidase, in Rome III IBS patients and controls. Here, FMO5 is linked to irritable bowel syndrome.