Investigation of serum trimethylamine N-oxide levels in irritable bowel syndrome and inflammatory bowel diseases

Irritable bowel syndrome (IBS) is the most common functional gastrointestinal system disease worldwide, characterized by chronic abdominal pain, relieved by defecation, negatively affecting life comfort and productivity. Ulcerative Colitis (UC) and Crohn's Disease (CD) are inflammatory bowel diseases (IBD) in which genetic, environmental and intestinal microbial factors play a role in the pathogenesis of which the exact cause is unknown. These diseases are chronic, progressive and recurrent. The serum trimethylamine n-oxide (TMAO) level varies depending on the microbiota. Recent studies have shown that the microbiota and dysbiosis are important in diabetes mellitus, obesity, chronic kidney disease and metabolic diseases. The aim of this study is to determine the serum TMAO level in order to contribute to accelerating the diagnosis of IBS and IBD with a non-invasive examination. A total of 200 people have been included in study as 50 patients with a diagnosis of IBS, 50 patients with a diagnosis of UC, 50 patients with a diagnosis of CD, and 50 healthy controls. The serum part of the blood samples taken is separated and the TMAO level is evaluated in the serum samples. IBM SPSS Statistics Version 22.0 package program is used in the statistical analysis of the data. A result of (p< 0.05) was considered statistically significant in all analyzes. When IBS patients are compared with the control group, IL-10, TNF-α and IL-1β levels have been found to be significantly higher (p<0.001). However, IL-6 level has been found to be lower than the control group. When UC patients are compared with the control group, IL-10 and TNF-α levels have been found to be significantly higher (p<0.001). However, IL-6 levels have been found to be lower than the control group. TNF alpha level has been found to be high in Crohn's patients (p<0.001). However, IL-1 beta and IL-6 levels have been found to be lower when compared to the control group. Serum TMAO level has found to be significantly lower in IBS patients compared to the control group (p<0.001). Serum LPS level has been found to be significantly higher in Crohn's disease when compared to the other three groups (p<0.001). In our study, TMAO levels have been found to be significantly lower in UC patients compared to the control group (p<0.001). However, serum TMAO level has been found to be significantly higher in CD compared to the control group (p<0.001). The fact that colonic involvement is less common in Crohn's disease compared to ulcerative colitis makes us think that the reason for this difference may be related to colonic involvement; We think that new multicenter studies with a larger population are needed in order to use TMAO as a biomarker in IBD. Keywords: Irritable Bowel Syndrome, Ulcerative Colitis, Crohn's Disease, TMAO