Influence of Lactobacillus and Bifidobacterium Combination on the Gut Microbiota, Clinical Course, and Local Gut Inflammation in Patients with Ulcerative Colitis: A Preliminary, Single-center, Open-label Study

Background: Ulcerative colitis (UC) is one of the chronic, relapsing, inflammatory disorders of the gut and is characterized by inflammation limited in most cases to the colon. Since gut microbiota play a critical role in the development and perpetuation of intestinal inflammation, the addition of probiotics to this complex system may exert a positive influence on gut inflammatory reactions. Methods: A single center, open-label, intention-to-treat study involving patients with moderate-to-severe UC was performed to check whether a probiotic mixture containing Lactobacillus plantarum, Lactobacillus rhamnosus, and Bifidobacterium longum given together with a standard treatment could decrease clinical and histopathology indexes for UC evaluation. Results: The mixture given once a day for at least 2 months together with mesalazine and ciprofloxacin to patients in the acute phase of UC significantly reduced their Mayo Clinic Index values. Moreover, numbers of lactobacilli isolated from patients feces were significantly increased, while those of Gram-negative rods decreased. The mixture given together with mesalazine to patients with UC in remission also caused a decrease of their clinical scores, but a more prominent and significant decrease of the histopathological index values in biopsy samples was observed. Conclusions: Supplementation of standard therapy with the probiotic mixture used in this study was efficacious in inducing and maintaining remission in UC, and this effect was related to modulation of dysbiosis in the gut microbiota.