Fecal Microbiota Transplantation for Disorders of Gut-Brain Interaction: Current Insights, Effectiveness, and Future...

Dysbiosis can disrupt intestinal barrier integrity and impact the immune and nervous systems, playing a significant role in developing disorders of gut-brain interaction (DGBI). This review aims to provide a comprehensive understanding of dysbiosis and its role in DGBI while examining the latest advancements in fecal microbiota transplantation (FMT). It also highlights key challenges in the field and outlines critical directions for future research to optimize FMT strategies, ultimately improving patient outcomes in this evolving treatment area.

In DGBI, dysbiosis triggers immune responses, increases gut permeability, and disrupts nervous system signaling, with contributing factors including diet, antibiotics, stress, and infections. Individuals with DGBI exhibit distinct microbial imbalances, such as an increased Firmicutes-to-Bacteroidetes ratio and reduced beneficial bacteria. FMT has shown mixed results, with factors like patient selection, treatment protocols, and microbiome diversity influencing outcomes. While FMT can improve symptoms in refractory irritable bowel syndrome (IBS), effects may fade over time, requiring repeat treatments. Future FMT approaches should focus on targeted microbial interventions, considering the role of archaea, fungi, and microbial metabolites, while prioritizing optimal donor selection and large-scale trials for long-term efficacy. Despite the promising findings, FMT has not yet been widely endorsed in clinical guidelines due to the variability and heterogeneity of the data available. While much of the research has focused on IBS, studies have also explored the impact of FMT on other conditions such as functional diarrhea, functional constipation, and functional dyspepsia, which all exhibit altered microbial profiles.