In the last decades fecal microbiota transplantation (FMT) has been established as a highly effective option in the treatment of recurrent Clostridioides difficile infection (rCDI), with a success rate of nearly 90%. For this reason, it is recommended by international guidelines as a treatment option for this indication in clinical practice. Recently, a considerable body of evidences, suggest FMT as an effective and safe treatment in patients affected by Ulcerative Colitis (UC). In a recent meta-analysis of 324 subjects with UC, 30.4% of patients achieved both clinical and endoscopic remission after FMT compared to placebo (9.8%, P\<0.00001). However, among the various published trials there is a fair variability in terms of methods and results, which are not comparable to those obtained in the rCDI. Nowadays, one of the most critical factors involved in the effectiveness of FMT in UC patients, is the choice of the donor. In addition, several studies have shown that some donors are associated with a higher clinical response rate than others. This hypothesis has been demonstrated in patients affected by irritable bowel syndrome, in which the use of a super-donor (a healthy person who has the predictive clinical and lifestyle characteristics of a healthy microbiota, and with a microbial profile associated with favorable clinical conditions) resulted in significantly higher clinical efficacy rates than placebo, similar to those obtained in rCDI (89%). Currently, studies that explored the efficacy of the super-donor FMT in UC patients are not yet available. Aim of this study is to investigate the efficacy of super - donor FMT, compared with placebo FMT, in the treatment of UC. The investigators will randomize adult patients with a recent diagnosis of UC to FMT from super - donors or placebo, by colonoscopy (first infusion) and capsules administration. Then, patients will be followed up 2 months after FMT.