Seher Khan

Background:   Irritable bowel syndrome (IBS) is a disorder of gut–brain interaction characterized by recurrent abdominal pain and altered bowel habits without structural pathology. IBS affects approximately 10–15% of the global population and is associated with significant impairment in quality of life, psychiatric comorbidity, and healthcare utilization.¹ Current therapies primarily target symptoms rather than the underlying mechanisms driving disease progression. Emerging evidence suggests that visceral hypersensitivity in IBS results from complex neuroimmune interactions involving epithelial barrier dysfunction, mucosal immune activation, oxidative stress, and dysregulated brain–gut signaling.²˒³ Mesenchymal stem cell (MSC)-derived exosomes have recently gained attention as a novel cell-free therapeutic strategy capable of targeting multiple components of this pathophysiologic cascade.

Objective: To review the mechanistic role of MSC-derived exosomes in the treatment of IBS, with emphasis on neuroimmune modulation, oxidative stress reduction, epithelial barrier repair, and regulation of visceral hypersensitivity.

Search Methods: A literature review was conducted using PubMed and Google Scholar databases for studies published between 2017 and 2025. Search terms and MeSH keywords included “irritable bowel syndrome,” “mesenchymal stem cells,” “MSC-derived exosomes,” “visceral hypersensitivity,” “Nrf2/HO-1,” “intestinal permeability,” “serotonin brain-gut axis,” “pyroptosis,” and “TSG-6.” Primary mechanistic studies evaluating MSC therapy and MSC-derived extracellular vesicles in animal models of IBS and intestinal inflammation were included.

Results: IBS pathogenesis involves disruption of the gut–brain axis, epithelial barrier dysfunction, low-grade mucosal inflammation, and central sensitization.²˒³ Gao et al demonstrated that human umbilical cord MSCs restored intestinal barrier integrity in IBS-D rat models by increasing expression of tight junction proteins ZO-1 and occludin while reducing pro-inflammatory cytokines including TNF-α and IL-6.⁶ These findings suggested that therapeutic effects were mediated primarily through paracrine signaling mechanisms rather than long-term stem cell engraftment. Liu et al further demonstrated that bone marrow MSC-derived exosomes reduced chronic visceral pain in IBS rat models through activation of the Nrf2/HO-1 antioxidant signaling pathway within spinal neurons.⁷ Exosome administration significantly decreased oxidative stress markers and visceral hypersensitivity, while pharmacologic inhibition of Nrf2 reversed these effects, confirming pathway dependence. Sun et al showed that adipose-derived MSC apoptotic vesicles normalized dysregulated serotonin signaling within the gut–brain axis and reduced visceral hypersensitivity in stress-induced IBS mouse models.⁸ Additional studies identified exosomal TSG-6 as a key mediator of intestinal barrier repair and suppression of NLRP3 inflammasome-mediated pyroptosis, thereby reducing upstream inflammatory drivers of neuroimmune sensitization.⁹˒¹⁰

Conclusion:   MSC-derived exosomes target multiple mechanistic pathways implicated in IBS, including oxidative stress, neuroimmune activation, epithelial barrier dysfunction, and serotonergic dysregulation. These findings support the potential of MSC-derived exosomes as a novel mechanism-based, cell-free therapeutic strategy for IBS. Further research is needed to determine optimal dosing, route of administration, reproducibility across IBS subtypes, and translational feasibility in human clinical trials.

Works Cited

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2. Soufan F, Khalaf K, Hamed H, et al. The gut–brain axis in irritable bowel syndrome: pathophysiology and emerging therapeutic strategies. Front Neurosci. 2025;19:1298452.
3. Cheng X, Liu S, Xu D, et al. Gut microbiota and irritable bowel syndrome: mechanisms and therapeutic implications. Int J Mol Sci. 2024;25(18):10123.
4. Gao Y, et al. Human umbilical cord mesenchymal stem cells alleviated diarrhea-type irritable bowel syndrome by improving intestinal function. World J Gastroenterol. 2025. PMID: 41480397.
5. Liu Y, Li M, Lian X, et al. Mesenchymal stem cells’ exosomes alleviate chronic visceral pain through Nrf-2-mediated oxidative stress pathway in rats. Pain Rep. 2025;10(6):e1372.
6. Sun Y, Wu D, Lu L, et al. Mesenchymal stem cell-derived apoptotic vesicles regulate irritable bowel syndrome in mice via the 5-HT brain-gut axis. Stem Cell Res Ther. 2025;16:326.
7. Wu B, Su S, Wang X, et al. Bone marrow MSC-derived exosomes alleviate DSS-induced inflammatory bowel disease through inhibiting intestinal epithelial cell pyroptosis via delivery of TSG-6. Front Immunol. 2025;16:1601591.
8. Yang S, Liang X, Song J, et al. A novel therapeutic approach for inflammatory bowel disease by exosomes derived from human umbilical cord MSCs to repair intestinal barrier via TSG-6. Stem Cell Res Ther. 2021;12:315.