Ulcerative colitis (UC) is a chronic inflammatory disease of the colon characterized by superficial mucosal inflammation. Treatment aims to achieve and maintain remission, improve quality of life, and minimize complications. Advanced therapies, including biologics and small molecules, have significantly improved UC management by targeting specific inflammatory pathways. However, due to the multifactorial nature of UC-driven by genetic, environmental, and microbial factors-many patients do not achieve sustained remission, highlighting a therapeutic ceiling. Gut microbial dysbiosis and immune dysregulation are central to UC pathogenesis, with diet playing a critical role in influencing the gut microbiome. While biologics and small molecules have limitations, innovative approaches like combining fecal microbiota transplantation (FMT) and dietary interventions with advanced therapies show promise. FMT restores microbial balance, modulates immunity, and reduces inflammation, while dietary modifications, such as anti-inflammatory diets, enhance FMT efficacy by creating a favorable environment for donor microbiota engraftment. The present study is designed to evaluate the efficacy of three different microbiome manipulation strategies- FMT, AID and FMT + AID in combination with advanced therapies in patients with active UC in a 2X2 factorial trial design. Patients would be randomized into four different arms: FMT, AID, FMT+AID and placebo. The advanced therapies (biologics or small molecules) would be given in all four arms as standard therapy. With this design the trial would answer two important questions: a) efficacy of combination treatment with advanced therapies and microbiome manipulation strategies in active UC, and b) comparative efficacy of different microbiome manipulation strategies.