Background: The COVID-19 pandemic has challenged the treatment of Clostridioides Difficile (CD)-infected patients given the increasing number of co-infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this context, fecal microbiota transplantation (FMT) shows promise in modulating the immune system’s function and alleviating the burdens associated with this condition. Methods: To achieve this goal, we performed a comparative, retrospective, single-center study on 86 patients (admitted between January 2020 and March 2022). We based our approach on specific inclusion criteria: 1. The study group included 46 co-infected patients (COVID-19 and CD) receiving antibiotics and FMT; 2. In the control group, 40 co-infected patients received antibiotics only. Our results showed no significant group differences in terms of gender, age, risk factors such as cardiovascular and neurological diseases, type 2 diabetes, and obesity (p > 0.05), or in pre-treatment inflammatory status, evaluated by white blood cell (WBC) count and C-reactive protein (CRP) levels. We report a significant decrease in inflammatory syndrome (CRP, WBC) in coinfected patients receiving FMT in addition to antibiotics (p < 0.05), with a lower relapse rate and mitigation of cramping and abdominal pain (91.3%). In addition, a higher level of fibrinogen, persistent moderate abdominal pain (82.5%), and a significantly higher CD infection relapse rate (42.5%) were recorded in co-infected patients treated only with antibiotics (p < 0.05). Conclusion: Our study provides new data to support the multiple benefits of FMT in the case of COVID-19 and CD co-infection by improving patients’ quality of life and inflammatory syndrome.