Profiles of Fear of Root Canal Treatment in Adult Endodontic Patients: A Cross-Sectional Study.

Irritable bowel syndrome (IBS) represents a common type of functional gastrointestinal disorder (FGID). Globally, approximately 20% of the general population is impacted by IBS, which substantially influences both quality of life and healthcare expenses (). Among the four IBS subtypes, the diarrhea-predominant form, IBS-D, is one of the most common and represents a particularly suitable model for investigating the anti-inflammatory mechanisms of EA, because low-grade intestinal inflammation is most consistently documented in this subtype compared to IBS-C or IBS-M. The cardinal symptoms of IBS-D—visceral hypersensitivity and diarrhea—are directly linked to NF-κB p65-driven inflammatory mediator release, creating a clear mechanistic target (, ). Recent advances in IBS-D therapeutics have expanded the available repertoire to include pharmacological agents such as rifaximin, antispasmodics, neuromodulators, and bile acid sequestrants, alongside non-pharmacological strategies including low-FODMAP diets, cognitive behavioral therapy, gut-directed hypnotherapy, and acupuncture. Despite this diversification, long-term clinical outcomes remain unsatisfactory due to adverse drug reactions, high treatment costs, and frequent disease recurrence, underscoring the urgent need for mechanism-based interventions with durable efficacy and minimal side effects (, ) Concurrently, mechanistic advances have repositioned low-grade intestinal mucosal inflammation as a central pathophysiological pillar, with the gut–brain axis, immune cell activation, barrier dysfunction, visceral hypersensitivity, and gut microbiota dysbiosis collectively driving symptom chronification. Within this network, NF-κB p65 signaling serves as a canonical molecular nexus that translates immune triggers into downstream cytokine release and epithelial barrier compromise, making it a particularly attractive target for mechanism-based therapy. Acupuncture involves inserting fine needles into specific acupoints to modulate meridian and qi flow, producing anti-inflammatory and therapeutic effects. Acupuncture has shown efficacy across numerous systemic diseases and is emerging as a promising non-pharmacological approach for FGIDs (). In multiple randomized controlled trials, acupuncture has been shown to be more effective than certain medications for IBS treatment. Its therapeutic effects may persist for up to 12 weeks, substantially alleviating symptoms like abdominal pain and diarrhea (–). These studies suggest that acupuncture has beneficial, long-term effects in the treatment of IBS-D. Nevertheless, the molecular biological mechanism in IBS-D is not fully understood, and the anti-inflammatory mechanism of acupuncture in IBS-D also remains to be fully explained. In the context of IBS-D pathophysiology, low-grade intestinal mucosal inflammation caused by mucosal barrier injury is central to the condition, which is associated with the onset and progression of abdominal pain, diarrhea, visceral hypersensitivity, and other clinical manifestations in patients (–). Disruption of the intestinal epithelial barrier in IBS-D is associated with immune cell activation and release of inflammatory mediators (), contributing to low-grade inflammation that exacerbates barrier dysfunction and visceral hypersensitivity. The nuclear factor (NF)-κB signaling cascade serves as a canonical pathway involved in inflammatory responses. It significantly contributes to cytokine regulation during inflammation by triggering the expression of downstream inflammatory mediators. This cascade upregulates pro-inflammatory cytokines including interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-α, and increases expression of the NOD-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome (, ). Electroacupuncture (EA), a widely utilized form of acupuncture, combines conventional acupuncture techniques with low-intensity electrical stimulation. This approach is utilized to alleviate inflammation and mitigate pain (). We selected ST25 (Tianshu, the front-mu point of the large intestine) and ST37 (Shangjuxu, the lower-he-sea point of the same meridian). This “He-Mu combination, ” is a canonical principle for treating disorders of the fu-organs (hollow viscera). This specific pairing is intended to harmonizes Yin-Yang, unblocks fu-qi and arrests diarrhea according to traditional theory, and contemporary studies show that EA at ST25 and ST37 suppresses intestinal inflammation and reduces visceral hypersensitivity in IBS-D (, ). EA was delivered at ST25 and ST37 using alternating dense-sparse frequencies (15 Hz/2 Hz), parameters selected to maximize neuromodulatory and anti-inflammatory effects. This study investigates EA as an integrated clinical protocol rather than dissecting the individual contributions of acupoint selection, needle insertion, or electrical stimulation. Our objective is to identify the downstream molecular pathways engaged by this standardized intervention.