Fecal microbiota transplantation alleviates mild‐moderate COVID‐19 associated diarrhoea and depression symptoms: A prospective study of a randomized, double‐blind clinical trial

Currently, the emergence of the endemic Coronavirus disease (COVID‐19) situation still poses a serious threat to public health. However, it remains elusive about the role of fecal microbiota transplantation in treating COVID‐19. We performed a randomized, double‐blind, placebo‐controlled clinical trial enrolling a cohort of 40 COVID‐19 patients with mild‐moderate symptoms. Our results showed that fecal microbiota transplantation provided an amelioration in diarrhoea (p = 0.026) of digestive system and depression (p = 0.006) of neuropsychiatric‐related symptom in COVID‐19 patients, respectively. Meanwhile, we found that the number of patients with diarrhoea decreased from 19 to 0 on day 7 after fecal microbiota transplantation treatment, and it was statistically changed compared to the placebo group (p = 0.047). Of note, the serum concentration of aspartate aminotransferase‐to‐alanine aminotransferase ratio (AST/ALT, fecal microbiota transplantation, pre vs. post: 0.966 vs. 0.817), a biomarker for predicting long COVID‐19, was significantly reduced by fecal microbiota transplantation. In all, our study supports that fecal microbiota transplantation could be a novel therapeutic strategy for COVID‐19 patients with diarrhoea and depressive symptoms, which is potentially valuable in ameliorating long COVID‐19 symptoms. Author Summary Although public attention towards the SARS‐CoV‐2 is decreasing, the emergence of new variants and the lingering aftermath of long COVID, which includes gastrointestinal and psychiatric symptoms, remains adverse effects on public health. Here, a randomized, double‐blind, placebo‐controlled clinical trial enrolling a cohort of 40 COVID‐19 patients with mild‐moderate symptoms was performed in our study. Our research revealed that fecal microbiota transplantation (FMT) led to alleviation in both diarrhea and depression symptoms among COVID‐19 patients. Additionally, the serum concentration of AST/ALT ratio, a biomarker for predicting long COVID‐19, showed a significant reduction following fecal microbiota transplantation. In conclusion, our research introduces an innovative treatment for COVID‐19 patients experiencing diarrhea and depressive symptoms, while is potentially valuable in ameliorating long COVID‐19 symptoms.