Combined Synbiotics and Omega-3 Polyunsaturated Fatty Acids Enhance Clinical and Histological Recovery in DSS-Induced Ulcerative Colitis: An Experimental Study in Rats

Background/Objectives: Ulcerative colitis (UC) is a chronic inflammatory bowel disease in which alterations in the gut microbiota and dietary lipid composition play a central role; this study aimed to evaluate the effects of synbiotics, omega-3 polyunsaturated fatty acids, and their combination on clinical, macroscopic, microbiological, and histopathological outcomes in dextran sodium sulfate (DSS)-induced colitis in Wistar rats. Methods: Seventy-two male Wistar rats were randomly allocated to four groups (n = 18/group) and received 5% DSS in drinking water for eight days to induce colitis. Following DSS withdrawal and histological confirmation of colitis in sentinel animals, groups were treated for 8 days as follows: DSS (control), DSS-S (synbiotics, Ecologic® 825), DSS-Ω3 (omega-3 fatty acid-enriched diet, ProSure®), or DSS-S&Ω3 (combined therapy). Eight rats per group were sacrificed on days 4 and 8 post-DSS. Body weight, Disease Activity Index (DAI), distal colon length, hematologic parameters, bacterial translocation to the liver and mesenteric lymph nodes, histological colitis score, and myeloperoxidase (MPO)-positive cell counts were assessed. Results: DSS induced severe colitis characterized by diarrhea, rectal bleeding, and extensive mucosal erosions. After 8 days of treatment, the DSS-S&Ω3 group showed the greatest body-weight recovery (206.1→222.9 g, p < 0.05 vs. other groups), significantly preserved distal colon length, and the largest reduction in DAI (p < 0.05). Both the DSS-S and DSS-S&Ω3 groups demonstrated reduced bacterial translocation compared with DSS. The DSS-Ω3 group demonstrated persistent MPO-positive neutrophil infiltration compared with the DSS-S and DSS-S&Ω3 groups, whereas combined therapy was associated with lower MPO-positive cell counts. Histological colitis scores were significantly improved only in the DSS-S&Ω3 group (p < 0.05). Conclusions: In this DSS colitis model, the DSS-S&Ω3 group demonstrated superior clinical and histological outcomes compared with DSS-S or DSS-Ω3 alone, supporting further evaluation of combined synbiotic and omega-3 therapy as an adjunctive approach in ulcerative colitis.