Fecal microbiota transplantation is associated with improved aspects of mental health of patients with recurrent Clostridioides difficile infections: Effect of FMT on affect in rCDI patients

Background The microbiota of the gut contributes to human mental health through the gut-brain axis. Treatment with fecal microbiota transplantation (FMT) offers the opportunity to explore the effects of modification of the microbiota on mental health in patients with a perturbed gut microbiota after multiple recurrent Clostridioides difficile infections (rCDI). Methods Symptoms of anxiety and depression, as well as self-rated health, happiness and dispositional optimism were assessed pre-FMT (n = 49), and post-FMT at 4 (n = 49) and 26 weeks (n = 34) in 49 rCDI patients, treated with FMT using feces from healthy donors. Results Patients had a mean age of 68.4 years, and 67.3% were female. Improvements of self-rated health (p < 0.001) and a decrease in severity of depression (p < 0.001) and anxiety symptoms (p = 0.045) were observed 4 weeks after FMT. These improvements persisted until week 26. No changes were found for happiness and dispositional optimism. The improvement of mental health was statistically independent of the immediate success of FMT, though the number of patients who developed a relapse within 2 months after FMT was low. Limitations Observational study without a control group. Conclusion FMT was associated with significant improvements of severity of depression and anxiety symptoms, which persisted until 6 months after FMT. Future larger studies should answer the question whether these effects are associated with clinical recovery, or whether they are partly mediated through gut microbiota changes on psychological wellbeing.