Introduction: The gut-brain axis has emerged as a crucial research area, emphasizing the intricate relationship between gastrointestinal health and mental well-being. Irritable Bowel Syndrome (IBS) and Inflammatory Bowel Disease (IBD) are gastrointestinal disorders that not only affect digestive function but also frequently co-occur with psychiatric conditions, such as anxiety and depression. Research suggests that the gut microbiome may be a key factor in this gut-brain connection, with specific microbiota influencing brain function and behaviour via neurotransmitter production and inflammation modulation. Fecal matter transplantation (FMT), the transfer of healthy gut microbiota to treat gastrointestinal conditions by restoring healthy microbes, has shown promise for addressing comorbid psychological symptoms. This review evaluates the evidence on using FMTs as a potential concurrent treatment of both psychological comorbidities and gastrointestinal symptoms among IBS and IBD patients. Methods: A review of the current literature was performed by searching for keywords using scientific electronic databases. Keywords used to search for articles included “fecal microbiota transplantation,” “FMT”, “comorbidity”, “gut-brain axis,” “mental health,” “depression,” “anxiety,” “irritable bowel syndrome,” “inflammatory bowel disease,” and “gut dysbiosis”. Articles were screened and selected based on quality and relevance. Results: Animal IBS models demonstrate a significant effect of FMT for initiating and treating psychological symptoms. Similarly, clinical trials have proven FMT to alleviate psychological symptoms among IBS patients by restoring healthy microbiota, but long-term effects require further investigation. Preclinical IBD animal studies support a causal relationship between gut microbiota, inflammation, and symptoms of anxiety, depression. Clinical evidence further supports FMT for IBD mental health comorbidities, suggesting that gut alterations offer relief from symptoms. Discussion: Results support the therapeutic potential of FMT in improving gastrointestinal and psychological symptoms among IBS and IBD patients. These conclusions remain preliminary due to a lack of homogeneity across studies, particularly in donor selection, administration route, and outcome measures, which limits the overall generalizability of results. Future research should address heterogeneous methodology to standardize protocols, as well as include larger and more diverse samples to inform clinical implementation. Conclusion: This review suggests that FMT may be a potential treatment for both gastrointestinal and psychological symptoms.
Matthew Mifsud (Tue,) studied this question.