Advancements in Immunomodulatory Therapies for IBD and Their Interplay With the Gut-Brain Axis: An Updated Review of Current Literature and Beyond

The incidence of inflammatory bowel disease (IBD), characterized by chronic gastrointestinal inflammation, has significantly increased over the last two decades. Concurrently, advancements in treatment strategies have accelerated, aiming not only to induce but also to maintain remission. Emerging evidence highlights the intricate bidirectional relationship between the gut and brain, forming the gut-brain axis, which is now a major therapeutic target.

This narrative review synthesizes findings from a wide range of research studies to summarize IBD incidence trends, underlying pathophysiological mechanisms, and recent therapeutic advancements. A major focus is placed on dysregulated immunomodulation and its role in disease progression. The review examines conventional treatments such as aminosalicylates and corticosteroids, surgical interventions, and newer therapies targeting the gut-brain microbiota axis, including biological agents, stem cell therapy, probiotics, and fecal microbiota transplantation (FMT).

Recent advancements in immunomodulatory therapies have significantly improved patient outcomes. Biological agents such as infliximab and vedolizumab have demonstrated remission rates of 40%-69% in IBD patients, with infliximab reducing colectomy. Rates to 10% at 54 weeks. Meanwhile, fecal microbiota transplantation (FMT) has emerged as a promising therapy for ulcerative colitis, with trials reporting 87.1% clinical remission at 48 weeks compared to 66.7% in the placebo group, along with higher endoscopic and histological remission rates. A trial on multidonor-intensive FMT found a 27% clinical remission rate at week 8, significantly higher than 8% in the placebo group, reinforcing its potential as an adjunct therapy in IBD. By examining their interplay with the gut-brain axis, this review provides insights into the mechanisms and clinical relevance of these therapies, paving the way for more targeted and effective IBD management strategies.