This article systematically elucidates the critical role of the enteric nervous system (ENS) in Clostridioides difficile infection (CDI), revealing direct toxin-induced damage to enteric neurons and glial cells and the resulting gastrointestinal dysfunction. It provides new insights into understanding post-infectious gastrointestinal motility disorders.
Literature Overview
This article, 'The Role of the Enteric Nervous System in the Pathogenesis of Clostridioides difficile Infection,' published in Nature Reviews. Gastroenterology & Hepatology, reviews and summarizes structural and functional changes in the enteric nervous system (ENS) during Clostridioides difficile infection (CDI), as well as its contribution to disease progression and post-infection gastrointestinal dysfunction. The study highlights that C. difficile toxins directly target enteric neurons and glial cells, triggering cell death, neuroinflammation, and secretory diarrhea, while exacerbating intestinal injury through multiple signaling pathways. Furthermore, interactions between the ENS and the immune system play a significant role in CDI pathophysiology, suggesting that the ENS may represent a novel therapeutic target. The article also discusses the potential mechanisms of ENS plasticity in post-infectious complications such as irritable bowel syndrome (IBS). The paragraph is coherent and logically structured, ending with a Chinese period.Background Knowledge
Clostridioides difficile infection (CDI) is the leading cause of hospital-acquired diarrhea worldwide. It is characterized by gut microbiota dysbiosis following antibiotic use, leading to overgrowth of C. difficile and release of toxins TcdA and TcdB, which trigger intestinal inflammation, epithelial barrier disruption, and severe diarrhea. In recent years, increasing evidence indicates that beyond epithelial and immune systems, the enteric nervous system (ENS) also plays a profound role in CDI pathophysiology. The ENS, often called the 'second brain,' consists of millions of neurons and glial cells distributed in the myenteric and submucosal plexuses, regulating gut motility, secretion, and barrier function. Studies have shown that up to 30% of CDI patients may develop post-infectious irritable bowel syndrome (PI-IBS), presenting with persistent gastrointestinal motility disorders, suggesting a key role of the ENS in long-term complications. However, traditional research has largely focused on the effects of toxins on epithelial and immune cells, with limited understanding of direct effects on the ENS. Recent in vitro and animal model studies have found that TcdA and TcdB can enter enteric neurons and glial cells via receptors such as FZD, inducing RHO GTPase inactivation, oxidative stress, inflammatory cytokine release, and apoptosis. Additionally, abnormal release of neurotransmitters such as substance P (SP), CGRP, and VIP can exacerbate inflammation and secretory diarrhea. Although preliminary mechanisms have been revealed, it remains unclear whether the ENS acts as a passive target or an active participant in CDI, what its regenerative capacity is, and how it regulates immune responses. This review integrates current research progress on the role of the ENS in CDI, emphasizing its bidirectional regulatory functions in disease onset and outcomes, and provides a theoretical basis for developing novel therapeutic strategies targeting the neuro-immune axis.
Research Methods and Experiments
This article systematically reviews the direct and indirect effects of Clostridioides difficile toxins on the enteric nervous system (ENS), based on extensive published in vitro, ex vivo, and animal model studies. The research integrates experimental data from human tissue samples, mouse models, neuronal cell lines (e.g., SH-SY5Y, NT2-N), and primary enteric neurons and glial cells. Using techniques such as immunohistochemistry, qPCR, Western blot, calcium imaging, and behavioral analysis, the study assessed structural and functional changes in the ENS following toxin exposure, including neuronal and glial cell death, inflammatory cytokine release, neurotransmitter expression, and intestinal motility. Additionally, gene knockout mouse models (e.g., FZD receptor deletion, P2X7R deletion, A2B receptor deletion) were used to investigate the roles of specific signaling pathways in ENS responses. The study also analyzed expression levels of glial activation markers such as S100B and GFAP in tissue and stool samples from CDI patients to validate the clinical relevance of animal models.Key Conclusions and Perspectives
Research Significance and Prospects
This study systematically reveals the central role of the enteric nervous system in Clostridioides difficile infection, moving beyond the traditional focus on epithelial and immune cells, and positions the ENS as a key regulator of disease progression and complications. This finding provides new insights into the mechanisms underlying post-infectious gastrointestinal motility disorders, particularly explaining why some patients continue to experience IBS-like symptoms after pathogen clearance. Targeting ENS protection or repair pathways—such as inhibiting P2X7R, A2B receptors, or the S100B-RAGE axis—may offer novel therapeutic strategies that not only control acute symptoms but also prevent long-term complications.
Future research should further explore the dynamic changes of the ENS at different stages of CDI, using spatial transcriptomics and single-cell sequencing to dissect responses of specific neuronal subpopulations. Developing animal models that more closely mimic human disease, especially those simulating non-constipated PI-IBS, will help validate potential therapeutic targets. Additionally, investigating the regulatory effects of gut microbiota metabolites (e.g., short-chain fatty acids) on ENS function may uncover new mechanisms involving the microbiota-gut-brain axis in CDI. Ultimately, interventions targeting the ENS hold promise for improving overall outcomes in CDI patients.
Conclusion
This article comprehensively summarizes the pathophysiological role of the enteric nervous system in Clostridioides difficile infection, emphasizing that the ENS is not merely a passive target of toxins, but a key participant in disease progression and post-infectious complications. The study demonstrates that TcdA and TcdB directly damage enteric neurons and glial cells through multiple mechanisms, triggering neuroinflammation, cell death, and functional impairment. Simultaneously, the ENS engages in bidirectional interactions with the immune system via neurotransmitter and inflammatory cytokine release, amplifying intestinal injury. Post-infectious gastrointestinal motility disorders may stem from persistent structural and functional alterations in the ENS, particularly an imbalance between neural regeneration and damage. This review provides a new dimension for understanding the complex mechanisms of CDI and proposes targeting neuroprotective pathways as a potential therapeutic strategy. Future research should focus on developing ENS-specific interventions and using advanced models and omics technologies to deeply elucidate its dynamic role in disease, ultimately enabling dual management of both acute and long-term complications of CDI. These advances are expected to significantly improve patient quality of life and advance the field of neurogastroimmunology.
