Effect of TNF-α inhibitors on microbiota composition and immune response in patients with inflammatory bowel disease

One of the most common used therapies in inflammatory bowel diseases (IBD) treatment are inhibitors of a cytokine TNF-α. Nevertheless, up to one third of IBD patients stop respond to this therapy for unknown reason. In these days, there are not any ideal biomarkers which could predict patient's long- term response to anti-TNF-α therapy. Because the gut microbiota composition changes are tightly related to the pathogenesis of IBD, my aim in this thesis was to find out if these changes in composition are happening also due the therapy by inhibitors of TNF-α as well. Moreover, I tried to find out if there are changes in production of serum biomarkers related to the gut barrier damage and to the immune response associated with microbial translocation. Also, I focused on the immune response of IBD patients against common gut commensal bacterial antigens during the anti-TNF-α therapy. In our study, we collected for these purposes stool or blood samples from 46 IBD patients before the therapy and at 38th week from the start of the therapy and 39 healthy controls. I found that IBD patients had higher bacterial diversity (α-diversity) as well as different bacterial composition across observed groups (β-diversity) at 38th week of the anti-TNF-α therapy than before the therapy. When I divided IBD patients..